AA mileage purchase could be reimbursed, because AA sells the miles directly, rather than outsourcing. However, it's not cost effective to buy a tiny amount of miles, and if you buy a large amount the system will likely not mistake the transaction for a fee.
I have bad news, and two negative data points. I tried this with direct mile purchases from AA.com (not mileage multiplier) for amounts a bit above and a bit below $100, and neither worked.