I bought a 207 just like brians non running for about 100.00
I wouldn't spend more than 200.00 on a non running moped.
Mine needed a new thyristor, petcock, plugs, and gas tank cleaned. Yours would probably need that too. Remember the decompression lever is to turn off the motor so you don't need to pull it while your starting it.
I also bought a 210 motor (single speed) to swap onto my 207 but from the blogs it might not match up correctly. Electrical stuff should work fine but I believe the motor mounts wont match up. I didn't try yet.