how many feedback does the guy have? you may email his previous seller to see if they took western union money transfer from him.
I fail to see why western union is a bad thing domestically.
as a seller, I have done many deals other sellers on here wouldn't do because they assume they will get scammed on ebay.
I had taken personal check and shipped out the item right away.
I had sent a $300 digicam to PO BOX for a buyer.
I never have problem with my buyers.
ebay is big, the chance that you will get scammed it very small. it is always good to play it safe, but you should evalute your buyer before he is trying to scam you.
it is probably better to work it out with your buyer before relisting it. I have been there and done it, it was just hassle. again, you don't want to leave your seller a neg or get a neg from that guy. sometimes, you have to bend over with your rules. of course, as long as you get the money.