Toyota Corolla E12 Downshift Problems

[BenWR]

Hi there, within the past month or so my 1.6 rolla has been grinding/crunching when downshifting into second, it usually happens at about 3k revs+ But if I let the clutch out slowly it tends not to happen, though perhaps that's just down to the lower revs. It doesn't grind/crunch when going from first to second and all the other gears are smooth so I was wondering what everyone thought this could be, will be getting it checked out ASAP but I wanted to get any idea at the kind of price I could potentially be expecting as i know tranny related issues don't tend to be cheap

Cheers