It's pretty unfair isn't it?
Don't know about anyplace where you can register a complaint about this, since it is actually common practice with international companies...
last time I ordered from Foundry I found out I could circumvent the problem. while searching for products and filling my basket I had my settings on UK. While filling in the details for the address I changed to the Netherlands. Lo and behold, I could pay in pound sterling and payed for the exchange costst myself

I guess it was (is?) a bug in their system, but I can't really feel that guilty about it since the high exchange range doesn't have to do anyhting with the shipping charges.
Might be that this "problem" in the online store is now fixed, but might be useful to give it a try