- Less than $30 for electronics, receiver included
- $1 - $15 for the airframe
- Planes are somewhat "disposable" -- if you crash one or if one does not work well, you can pull out the electronics and have a new model ready to go in a couple of days
That's cheap enough that you can get a nice Turnigy 9x and still be able to get started for not much more than $100, everything included.
There's tons of information in the RCGroups Scratchbuilt Foamies Forum. Many of the world's foremost foamy designers put their designs here. Here's some models which I think are pretty good.
EzFly -- a great little flyer and trainer from EPP. I love mine!
EPPYak55 -- another model by leadfeather, who did the EzFly. I'll make one of these soon!
F22 -- this is a sweet-flying plane that can turn on a dime. Andreas built a pair for us. I love flying mine, and it looks like it's going to be the gateway drug for Mark VandeWettering over at Brainwagon!
BluBaby -- one of the most famous scratch-built foamies. This is one of the first planes I built. The first one was so terrible I recycled it for parts without trying to get it to fly. I've got two built now (I learned a lot by building in pairs). Ironically I got busy on other things so they've never been maidened. I promise I'll do that soon!
Dollar Tree Delta -- I just saw this one on RCG -- very tempted to try it out, since it fits on one piece of dollar tree foam and looks like it can be put together in an hour.
Nutball -- of course, based on the classic Nutball, but uses the central body frame.