From: Vermont, USA
On the issue of updating prices, I obviously have no insight into your system. However, it would seem to me that your products have a fixed price (in US dollars) applied to them. There would then be this variable called "Discount" which is another field holding, erm, the discount. When the page is displayed, the price * the discount would reflect the price displayed to the user. So all you would have to do, in each scenario, is update the discount. Right?
In it's simplest form, that's what a normalise database would do. You can even throw in other factors...but essentially having a base and then variables for the base to work with would give the right results.
It seems to me, from the sound of it, that you have a different game list/price set for each country/region or it's not using a database system at all and is hard coded in the HTML which is why you were probably up until the early hours.
Believe me, I can envision and design many, many better systems than we currently have for mass price changes. In fact, I've been requesting those improvements from DR for quite some time now. Unfortunately, being able to imagine a better system has so far not actually gotten me one.