You do realize, of course, that you don't have to replace with new each and every time something minor breaks on the plane. Part of the hobby is learning to fix non-fatal damage. Sure, new wings and tails are relatively cheap, but when you move up into the larger more expensive planes, are you going to spend $50+ for new wings every time you put a little ding on one?

Get yourself a tube of 5 minute epoxy from the paint and adhesive aisle and a roll of packing tape from the stationery aisle at Wal-Mart. These will be your two best friends for reinforcing and repairing foamie planes.

Let's take that prop strike for example. Your brother didn't need to replace the wing if all it did was take a small chunk out of the trailing edge. Simply lay a piece of tape on the bottom of the wing, put the chunks back in, then lay another piece of tape over the top of the wing. Good as new.