I do both. If I get one in the early season when its hot, I drop it off on the way home right in the butchers walk-in. A "regular cut" which is roasts, backstraps, T-loins, and ground, cut, wrapped, frozen, labeled is $60.
When the weather cools off and I have some time to hang it, I'll do it myself. Usually I'll do straps, loins, cut the hams up for jerky, and rest is ground.
Whoever posted "backstraps without silver" is spot on, and if I have the time available and a cool day or two to hang, I prefer that way. Freezer paper and tape is much cheaper.