Okay, I have generally hung around this web site silently watching videos, etc., but I have to chip in my two cents... or whatever, considering I've lived in multiple places and dealt with multiple currencies.
In short, Steam is great IF you 1) don't move between multiple countries or 2) you NEVER have to deal with their customer support. If either of these are issues for you, give up the ghost: there is no point in using Steam.
My husband and I have had multiple bad experiences with Steam. When we lived in China, it was INSANELY slow to register and amazingly kludgy. We gave up playing our games on there because it just loaded worth crap and wasn't worth the effort. (And other games and sites did NOT have these issues -- at the same time, we were playing World of Warcraft!) Of course, moving around also caused game access issues because we purchased games in different places (our physical copy of Half-Life 2 came from China, for instance.)
However, the straw that broke the camel's back was dealing with their customer service, after we'd moved to Japan. Team Fortress 2 had a free demo up with a $10 special sale. My husband and I both downloaded it, we had a blast, decided to buy two copies. Went to pay for it and it, the system spat because our credit card is registered in the U.S. (At that time, we didn't have a Japanese credit card yet.)
Well, that was understandable -- we'd had the same issue before with other places, just contact customer service and it should be solved. We weren't upset at all. It's reasonable to say "wait a minute, wait a minute!" when the location of the purchaser does NOT match the billing location by a continent.
So we contacted their customer service. A day later, we got a confused form response that had nothing to do with our problem. So we e-mailed again. Another day passed with another nonsensical reply, we replied again. Then they said, "oh, it should be fine now." But by THEN the SALE had ended. We contacted them explaining all this -- and yes, I kept polite, I've worked customer service and it's a hellish job -- and we got the reply, FROM A MANAGER, "The sale is over and we cannot change our system to give you the sale price. Sorry."
So my husband wrote back a long explanation, and said, "What can you do? Is there ANYTHING you can do to make a customer happy?" Finally, the manager came back telling us how to BYPASS their security in checking IPs versus physical addresses so the issue wouldn't come up in the future -- but again told us there was no way they could change the price (or offer a credit, or whatever) for us since the sale was over. (No, I'm not going to tell you how to bypass the security. They shouldn't have to tell you how to cheat their system to do stuff. Something was amiss here.)
After that, we started looking around for another site to buy games from -- since they are insanely expensive if you buy games via Amazon Japan, we ENVY the Aussies! -- and ended up settling down on Gamer's Gate. Of course, our first purchase, the same problem came up! Within an hour the problem was solved and we had our purchase... and the next purchase, they were slower to respond, the sale had ended, and they cheerfully gave us the sale price, anyway.
So, after that, I was done with Steam. I understand that Steam is terrific... IF YOU DON'T HAVE A PROBLEM. They're not the only ones like that, though... just have problems with Paypal sometime and you'll get the same show. I don't know what it is with some companies...