If its a project he's after...I have a 18.5" Giant XTC Team NRS with Rockshox SID rear shock and spare rear triangle. Top tube had a ding, been filled but needs paint (or sticker).
£120 collected.
I've a 2004/05 Kona Stinky frame, 17". It has a Fox Vanilla R shock, nearly new bearings.
I bought it as a spare frame/project. Bought all the parts, (forks, brakes, wheels, mechs, shifters, shims, bb etc) but can't be bothered to build it up Even though it'd only take a few hours.
Could do with a re-spray if he really wanted to but is perfectly useable as it is.
I've drilled out the cable stops to enable full outers to be run for the mechs.
If he'sserious about riding it downhill as well, I have a Medium size Ellsworth Dare frame I could part with. It makes for a nice rider and won't break the bank. Can be set-up with 5" or 6" travel depending on your choice of shock.