Sadly for me, Amazon charges me tax, so I rarely buy something from them because of that. Overstock.com and Buy.com have been good to me though and I cannot complain about them one bit.
Anyways, it's your choice like you said and I won't twist your arm. You won't really get it any cheaper then if the price does drop down to $399.99 like most assume will happen either this xmas or march of next year. So basically, if all happens like we think, you wouldn't pay any less then you can get it now with that deal from Sony with the credit card. But, if the price drop doesn't come through until say early summer of next year, you could likely find yourself paying more for a PS3 if you have to get one in march when all those great games come out.
For myself, the main reason why I bought a PS3 when I did was because of the news that Socom Confrontation was coming out and then the price cut on the 60gb version. I didn't expect the prices to drop any further the rest of this year (and hoping it still comes out this year) just so I have it and I can enjoy some of the games that come out from now until then that interest me. Like you, I do have a 360 as well and didn't really have to buy it then, but with the free movies (some I'll keep, couple I may ebay for some free money) it was worth it and I don't regret it one bit.
My pokemon brings all the nerds to the yard. And they're like, "You wanna trade cards?" Damn right, I wanna trade cards. I'll trade this, but not my charizard.
