The MSRP for new CZ 550's is $825.
CZ 550 American
I don't know what brand scope is on it that comes with it to know what it might be worth. I'd say based on what it runs new, that it is maybe worth it. If I were to bid, I'd bid the $429 and not use the buy it now and if someone out bid me, then so be it. His shipping seems high to me compared to some at $45 bucks. Then factor in any transfer fees from yur FFL. So if you get it for the $429. Then add the $45 for shipping. Now it's at $475. Then if your FFL charges say, $25 bucks and won't charge or doesn't have to collect tax, IS IT WORTH ROUGHLY $500 TO YOU?