He has a small business, he should have a lawyer on retainer anyway. As such there may be no cost for a conversation (of course check with the contract - generally there is a cost). Even if there is a cost, one conversation with a lawyer is not $800. The costs add up quick if he goes to court, but odds are good he only needs one conversation and so the costs are minimal. A bit of legal advice can go a long way.
If he does go to court with a lawyer the costs will be a lot more than $800, but he can sue for legal fees as well as the loss. If Meta is being unreasonable enough that it has to go to court he will get those fees. A judge will not like seeing this trivial cost go to trail, if it gets that far the judge will be looking to see who is not reasonable and slapping them with as many fees and costs as he can.