Enebias: If I was GOG, I think the most logical step I would take would be to implement a gift system based on GOG accounts rather than e-mail addresses, then charge the buyer the price used in the last region the recipient has been registered.
For example, if a Russian wanted to gift me Sacrifice he should choose "gift to GOG account: Enebias>choose game>checkout" rather than "choose game>checkout>send to enebias@ghost.com", then pay 9,99$ rather than the usual cheaper price due to me being in Italy.
Same goes for me: if I buy a game for a Russian account, I should pay the Russian price.
That way it wouldn't be necassry to always globally charge the highest sum, and there would not be a big differenc ein revenues. I don't know if this is feasible, though.
Also, it would probably kill gifting to anonymous people... I guess they should leave the system as it is under that aspect. "Redeem where you want, as long the price is equal or higher".
Something like that. Also a good idea!