Disney has the ability to change the terms at any time. So, while you can now stay at
DVC resorts other than the one at which you own, there is no guarantee that you will always be able to do that.
That said (and most people on this board will advise you to buy where you want to stay most), cost was more important for me when I purchased in 2000. I bought resale through The Timeshare Store--a 460 point contract for only $53 a point at Old Key West.
I bought where points cost the least, and where condo taxes were the smallest every year.
I never stay at Old Key West. Can't stand the place. If Disney ever decides that your only option is going to be to stay only at your home resort, I'll just sell my points. But it's already paid for itself and now the rooms cost us so little it's just a pleasure.
I always stay at the Wilderness Lodge Villas or the Beach Club Villas (and once at Boardwalk Villas just for a change, then at Sarasota Springs, which was too remote, like Old Key West). I generally have no trouble booking even at just five months out in the other resorts.
So, make your own choice, but there is NO reason to buy retail from Disney--that's very short run thinking. You'll save far more buying a resale.