Quoted from mg81:Just for the sake of argument contract law would likely say, the loss could be the difference in the contract price (what PinFever's original contract price was to purchase) and the current market price at the time PinFever learned the contract was being cancelled (repudiated) by the seller plus incidental damages.
This is a fairly common issue in contract law with rising market as sellers try to capture top dollar for their items.
But all of that being said, lots of unknowns, like what terms were actually in your contract that would let them break the deal, probably plenty. Also the split in values will likely be more than consumed in attorney's fees.
A receipt would not count as an enforceable contract to receive the goods (and that's all people receive in this case - there is no written contract other than a receipt given) - there is precedent on this from folks who sued a retailer who charged them for an item and sent them a receipt, but ran out of stock (and probably many more precedents). As long as the refund was timely given, out of luck.