I can guarantee you that the bass drum alone is worth over 250.00, the toms alone should fetch another 150 to 200 each. As for the cymbals and stands.....approx. 150 to 250 for the lot. If the set is incomplete as shown on the pic, I recommend you sell the pieces separately on e-bay.
Why dont you back up that gurantee right now and just buy them at the prices you quoted? Save him the hassle of pics, and a couple failed auctions, relist fees, answering questions for pics, etc.
They dont have that high value as orphans. Especially "abused," "neglected," orphans.