peugeot 206 broken 2nd gear?

I have a peugeot 206 1.4 glx 98.
When i shift down into or upto 2nd gear it clunks, i just called a garage and they quoted £495+vat!!! my cars only worth £1000, and i'm only getting it done to sell it?
How easy is it to fix whole box or can one gear be fixed?