FMS ( Flying Models Simulator )
If you are searching for a very cheap flight simulator, I mean really cheap zero dollars, I suggest getting this FMS. This is a freeware simulator with a very realistic model flying you will ever encounter. Maybe not the best but since it is free it is the best. You can also find many models to choose from in the internet. Anyway I can give you some links to download sites of the programs and the model aircrafts. You can fly helicopters, airplanes, gliders with incredible realism. You can also use your transmitter by plugging it in your CPU using USB but you have to make or purchase the cable in order for it to function.
Here are the download links:
