There are three parts to the answer to this, which is appropriate, because with Sony, Olympus, Panasonic, Fujifilm, and Sigma focusing on mirrorless designs, there are really only three companies making DSLRs: Pentax, Canon, and Nikon.

First, all Pentax DSLRs, even the entry-level models, have built-in autofocus motors. So, if that's really your main concern, there you go. Pentax has excellent compatibility with old lenses, and that's a route many Pentax enthusiasts take — although the bulk of the interesting old lenses are manual focus anyway. (But while I do love Pentax, I think you should read on to get the full picture.)

Second, Canon went straight to in-lens focus motors when the EOF mount was created in the 1980s. As Philip Kendall points out, read more about that here: Do all Canon DSLRs have in-body AF motors?

And, finally, for your primary concern, saving money because you won't have to buy AF-S lenses — well, maybe, but that's not the whole story. See Can I save money on lenses by buying a Nikon camera with an in-body autofocus motor? for more on this. Dan Wolfgang gives a great answer, and the key point is that while you can probably save money,

AF-S lenses often offer more than just internal motors: better optics are pretty standard. I while back I pulled out an old 35-80mm f4-5.6 AF-D "kit" lens and shot with it a little on my D300 and was amazed at how poor the optical quality of it was as compared to the 18-55mm AF-S "kit" lens. It wasn't bad, but the 18-55 was clearly better.

and, in general, the answers at How do camera body motors compare to in-lens motors for focusing? expand on this, with most of the advantages coming down in the "in-lens" camp. The Pentax Limited lenses provide an exception, because the lack of an AF motor allows them to be especially tiny. Compare the Pentax 40mm "pancake" lens with Canon's version — the Pentax is 70% of the weight and length.

There are three parts to the answer to this, which is appropriate, because with Sony, Olympus, Panasonic, Fujifilm, and Sigma focusing on mirrorless designs, there are really only three companies making DSLRs: Pentax, Canon, and Nikon.

First, all Pentax DSLRs, even the entry-level models, have built-in autofocus motors. So, if that's really your main concern, there you go. Pentax has excellent compatibility with old lenses, and that's a route many Pentax enthusiasts take — although the bulk of the interesting old lenses are manual focus anyway. (But while I do love Pentax, I think you should read on to get the full picture.)

Second, Canon went straight to in-lens focus motors when the EOS system EF mount was created in the late 1980s. As Philip Kendall points out, read more about that here: Do all Canon DSLRs have in-body AF motors?

And, finally, for your primary concern, saving money because you won't have to buy AF-S lenses — well, maybe, but that's not the whole story. See Can I save money on lenses by buying a Nikon camera with an in-body autofocus motor? for more on this. Dan Wolfgang gives a great answer, and the key point is that while you can probably save money,

AF-S lenses often offer more than just internal motors: better optics are pretty standard. I while back I pulled out an old 35-80mm f4-5.6 AF-D "kit" lens and shot with it a little on my D300 and was amazed at how poor the optical quality of it was as compared to the 18-55mm AF-S "kit" lens. It wasn't bad, but the 18-55 was clearly better.

and, in general, the answers at How do camera body motors compare to in-lens motors for focusing? expand on this, with most of the advantages coming down in the "in-lens" camp. The Pentax Limited lenses provide an exception, because the lack of an AF motor allows them to be especially tiny. Compare the Pentax 40mm "pancake" lens with Canon's version — the Pentax is 70% of the weight and length.

There are three parts to the answer to this, which is appropriate, because with Sony, Olympus, Panasonic, Fujifilm, and Sigma focusing on mirrorless designs, there are really only three companies making DSLRs: Pentax, Canon, and Nikon.

First, all Pentax DSLRs, even the entry-level models, have built-in autofocus motors. So, if that's really your main concern, there you go. Pentax has excellent compatibility with old lenses, and that's a route many Pentax enthusiasts take — although the bulk of the interesting old lenses are manual focus anyway. (But while I do love Pentax, I think you should read on to get the full picture.)

Second, Canon ditched its in-body focus motors when the EOF mount was created in the 1980s. As Philip Kendall points out, read more about that here: Do all Canon DSLRs have in-body AF motors?

And, finally, for your primary concern, saving money because you won't have to buy AF-S lenses — well, maybe, but that's not the whole story. See Can I save money on lenses by buying a Nikon camera with an in-body autofocus motor? for more on this. Dan Wolfgang gives a great answer, and the key point is that while you can probably save money,

AF-S lenses often offer more than just internal motors: better optics are pretty standard. I while back I pulled out an old 35-80mm f4-5.6 AF-D "kit" lens and shot with it a little on my D300 and was amazed at how poor the optical quality of it was as compared to the 18-55mm AF-S "kit" lens. It wasn't bad, but the 18-55 was clearly better.

and, in general, the answers at How do camera body motors compare to in-lens motors for focusing? expand on this, with most of the advantages coming down in the "in-lens" camp. The Pentax Limited lenses provide an exception, because the lack of an AF motor allows them to be especially tiny. Compare the Pentax 40mm "pancake" lens with Canon's version — the Pentax is 70% of the weight and length.

There are three parts to the answer to this, which is appropriate, because with Sony, Olympus, Panasonic, Fujifilm, and Sigma focusing on mirrorless designs, there are really only three companies making DSLRs: Pentax, Canon, and Nikon.

First, all Pentax DSLRs, even the entry-level models, have built-in autofocus motors. So, if that's really your main concern, there you go. Pentax has excellent compatibility with old lenses, and that's a route many Pentax enthusiasts take — although the bulk of the interesting old lenses are manual focus anyway. (But while I do love Pentax, I think you should read on to get the full picture.)

Second, Canon went straight to in-lens focus motors when the EOF mount was created in the 1980s. As Philip Kendall points out, read more about that here: Do all Canon DSLRs have in-body AF motors?

And, finally, for your primary concern, saving money because you won't have to buy AF-S lenses — well, maybe, but that's not the whole story. See Can I save money on lenses by buying a Nikon camera with an in-body autofocus motor? for more on this. Dan Wolfgang gives a great answer, and the key point is that while you can probably save money,

AF-S lenses often offer more than just internal motors: better optics are pretty standard. I while back I pulled out an old 35-80mm f4-5.6 AF-D "kit" lens and shot with it a little on my D300 and was amazed at how poor the optical quality of it was as compared to the 18-55mm AF-S "kit" lens. It wasn't bad, but the 18-55 was clearly better.

and, in general, the answers at How do camera body motors compare to in-lens motors for focusing? expand on this, with most of the advantages coming down in the "in-lens" camp. The Pentax Limited lenses provide an exception, because the lack of an AF motor allows them to be especially tiny. Compare the Pentax 40mm "pancake" lens with Canon's version — the Pentax is 70% of the weight and length.