Porsche Carrera 3.2 – G50 transmission

Hello, have a 88′ Carrera 3.2 with G50 gearbox, with which I have recently remained lying down. Only 2 gears can be switched, the 3rd and the 4th still the gearbox is not disassembled, so that I is not yet fully aware of the extent of the damage. However, the gearbox has run 252 tsd. Km and I fear bad things. Every serious mechanic has told me so far that there will certainly be nothing to do under 3,000 EURO. Are there used G50 gears? Greetings, Clemens.