I would go for the complete version (all campaigns and eye of the north) as it gives you the total experience. But yes, the game is 6.5 years old so it can be hard to find it on regular shops. However i am pretty sure that there are stil webshops who sell it (hopefully with a paying method that you can use).
I am euro and i dont have a creditcard either... luckily for me my parents have one which i can use when i want to buy things in the gw online shop or webshops.
However i often play with an USA friend who doesnt have a creditcard either. But he still can buy stuff in the same shops using "giftcards". I am not familiar with giftcards, but i assume those are cards that you can buy in regular shops and then use them elsewhere (like on the internet).... ?!
Good luck getting your copy of GW...
Btw, the webshop i use most is zavvi.com (webshop is located in the UK!!)... i just checked it for gw products. It still has GW trilogy for 18.45 euro (porto costs outside the UK are fixed to 1.15 euro?), but it also show
GW2 for 36.95 euro... to be released at march 30th 2012??
Source:
http://www.zavvi.com/elysium.search?...rch=guild+wars