Consider seeing if anyone has an old trainer in your club that they are getting rid of.

Typically you can find these for a song as everyone has them.

At worst you can then take the engine and good components and transfer them to a new airframe ending up with a top tier trainer at a greatly reduced price.

You could also purchase the airframe, engine and inexpensive servos and use your existing TX.

With an all new configuration you should be able to pull it off for around $250.00 using your own TX/RX.