Since then the price has fluctuated a little, mostly upwards (that I've seen anyway). For most of the 30 days it was hovering around $10 more than I paid, and as of this morning it was around $20 more than I paid. However, this morning, if you bought both the camera and an extra battery you could get the combined lot for about $15 less than I paid! This, 31 days after my purchase, and thus, out of price-guarantee territory. I hope that nobody bought it today and failed to see the bundle. Even if you don't need the extra battery (which, really, you don't because it lasts upwards of 500 shots) you save a decent amount of money by just dumping it on eBay.
I'd be very interested to learn exactly how Amazon sets their prices for an item at any given time. I'm sure that it's a closely guarded secret. I've seen reports in the past that logged-in users sometimes get different prices vs. non-logged in users browsing at the exact same time. This is actually pretty brilliant as Amazon has a huge database of buying preferences for its millions of customers and could theoretically alter prices one way or the other on items it thinks you are likely to purchase. My economics major brain is fascinated. Every 10 years or so I have to pretend that I actually remember something from my college education.