well $30 isn't much for a scam, you'd think they'd "sell" something more expensive... but the fact that they want the moneyorder left blank is a huge red flag. personally, i'd go elsewhere, again $30 isn't much but why take the risk. if the other person is for real, they should have no trouble giving you a name to put in, as well as a phone number to call for voice confirmation. you should be able to match the number up with the address, which at least reduces the chance of being scammed. this is in general, not just for $30 airport cards 🙂
best of all, paypal them from a credit card. let visa take the fall 🙂
pnw