IANAL but cant you sue people for breach of contract,
you can probably get the cost difference of the same product if you have to pay more elsewhere, this is the case with retail sales not sure about it with second hand private sales,
I had a situation with buying a laptop on ebay, got one for a bargain price but the seller made excuses about delivery, I was never going to get it for the same price elsewhere, had to pay alot more and considered sueing for the price difference,