If you guys want, gift me the blue coins and I'll buy GTA Complete for you.
Thanks for the offer, but I have most of the games already, was simply puzzled about differing availability and prices (still don't know where it costs 7,50 euro instead of 9,99 euro).
Yeah, GTA isn't visible with a German IP. I think it's because one of the GTA IIIs is banned. GG for me is "broken" anyway, as I see everything in $$ (quite good actually). Or they jsut said f*ck it, even banned games get displayed there for me.
If you want to buy on a foreign steam account, you need to use those "paysafecards" otherwise steam will check the nationality of your bank account/credit card and decline the purchase.
I suspected something like one game being banned (love our "Jugendschutz"), as that's usually the reason for discrepancies (and crippled versions).
For GG, using a proxy works well: Just initiate payment through the proxy, then (if you do not want to enter payment details through the proxy) close the window, log in without proxy, and pay.
Not sure what data steam uses for comparison. So far I only knew about adress and ip: I had a good friend who was in Sweden at the time buy left4dead2 with my account, and he had to change the adress to make it work. Payment was PayPal, though, so nothing to compare here.