What radio do you have? If its a decent one, you could just use it for your glow plane. If you have park receivers, you'd want to get a full range receiver, but if you have a full range already you're all set.

If you're looking to stay under $150, I'd try finding a used one at a swap meet or something (or in the classifieds here or on RCG). You can find all sorts of great deals on planes. I bet you could find a nice .40 sized sport plane in that price range.

Though don't forget you have to get the support equipment, fuel, fuel pump, glow plug igniter, starter, etc. But again, a lot of that you could find at a swap meet.