A simulator will undoubtably save you at least one airframe if you want to learn 3-D. You can learn the basic moves on the sim, then you can go out in the real world and learn how to do them for real. No sim is a substitute for actual flight time, but it can really help you to get the kinks worked out.

The hardest part for me when I learned inverted flying was to train my thumbs reflexes to push OUT when I bail, instead of PULLING it into the ground. Four hours and a sixpack of coors light got my thumb working more realiably Now I fly inverted alot. Sims can really help you to get alot more hours on the sticks, without the PITA of packing your gear, driving for half an hour, unpacking, flying (which is the good part), cleaning up and re-packing, driving, and un-packing everything again. Not to mention, you can't kill a simulator by dumb-thumbing it into the ground!

AFPD is a good sim- and relatively inexpensive.