What is this worth?

[Garfield2010]

I got a new 302 Rockshox with a u-turn and lockout funtion. It has been used once. My dad bought a new Mongoose 2 years back. He rode one race then won tyres at the lucky draw. When he came back from the shop where he won the tyres from he had a new shock on as the guy sold him a "lighter shock" for various reasons I dont care about. So he gave me the "old" shock. Needless to say it doesnt fit on my 26'er and have been lying around in my garage for 18 months now. I might just as well sell it.

 

What is it worth? Any buyers in Bfn?