gear box repair

[jawadarif]

hi ya, does looking for someone that can repair the gear box for evo 7 speed. mine make a sound in reverse and also sometime it wont go into reverse gear. also it make a rattle sound, when i put my clutch down it does away or if i rev it the noise goes away. looking at price for 2nd hand and they approx 500 to 650 and 300 labour on top, plus no guarantee it will work. by budget is 600max. the clutch as already been changed so cant be the clutch bearing.