Its worth only as much as someone is willing to pay, and from this its not hard to see there worth well over the original offer, but your forgetting the buyer would also need two trailers and probably a van aswell as spending a day collecting the items, your not going to find an enthusiast who needs two projects and bits (and the ones who want two projects + bits have no money), instead youll find someone who wishes to make money so will be looking to *steal* the items and make a profit, so either live with that, or put some work in (clearing the area around the items etc) and sell seperately.
Nicely put