How handy are you?
You can buy a new compressor for $250-300 and a new controller for approx $150 maybe dual voltage (12 DC/120 AC), and you will need a drier. You will need to have someone silver solder the new into the old setup, evacuate the system and slowly add R134A back into the system till you get the right level.
This assumes that you have no other leaks or obstructions in the expansion tube/orifice and the T'stat is good.