I am in the UK, everything on GOG.com is priced in US dollars, so it can be a little confusing when to comes how much I'd actually be paying for something.

Can you please add a UK currency across your site? Every other major online retailer has no problem doing this. Working out the rates myself will never be totally accurate, and generally a pain that shouldn't be required from a customer.

Is it really too much to ask?

Problem is that different banks use different conversion rates, not to mention foreign transaction fees. Your best bet would be to use PayPal, which does convert prices to your local currency, though at a worse exchange rate than banks.
Also, if GOG does introduce different currencies, only the $ prices will be stable, since the others will fluctuate due to conversions.

Man, I loved when the AUD was about the same rate as the US dollar, now it's all outta whack. I paid 25 dollars the other day on GOG and it cost me 28 in AUD

I typically go to google when I need to do currency conversion. For example typing '$10 in AUD ' in the browser search field returns 10.97 Australian Dollar.

No and yes.

This thread will be a history in hours. If you're serious about your request, I'd recommend voting for it in wishlist.

Just use xe.com and check with the provider of your payment method what exchange rate they use. Some will match pretty much what is displayed on xe.com others will charge slightly more. If it's truly difficult to work out how much something costs, then look at xe.com and round up to the nearest full pound (for example a $9.99 game should not cost more than £7).

At least then, you'll almost certainly be paying less than expected -- unless your payment method provider is really terrible one that is over charging you with the conversion...

As ET3D suggested Google is your friend in this. Just enter "$X,xx in GBP" in the search and Google will tell you the value in GBP using the currently valid exchange rate. Your bank/Paypal will add a bit on that, to make a profit, but that's unavoidable with currency conversions.

Nonononono...

We don't want that. We don't want this or we are getting too close to the Steam Store, with its national pricing scheme. I think using google to convert you prices or doing some math in your head once in a while isn't too much to be asked either...

I only use Monopoly money so I don't have this problem.

What JMich said - the only way to accurately know how much a purchase costs in UK pounds, is to know the transaction fees and the exact exchange rate your bank uses on the specific day you make a purchase, i.e. if you want such accuracy, you can't avoid the "pain", sorry.

I usually use xe.com myself, and allow for a few extra pence when buying from GOG.

The difference has usually been in the region of 10p or so.

Remember that he is from the UK. A foreign transaction fee in the neighbourhood of £1.5 is usual, and quite a bit more than what paypal would charge.

You mean there is a FIXED fee if charging a foreign transaction? Because I know of variable fees which are really low, like 0,2% or so, but if it is a fixed fee then yeah, it sucks, you are on the same boat as using paypal.