Where to buy comics

Hey guys, Hows it going. I am in a bit of a pickle. I have been bbuying my trade paperbacks from the book depository for a while nwo but as I get more and more into comics and start wanting to complete runs i find there stock lacking. Is there any other place where I could order them online. 

I live in Ireland and have tried Amazon UK but the price is so expensive, espeically after conversion from pounds to euro.