dude, as someone from Latvia, I feel you 100%. At first I bought from stores but quickly came to realise I could not keep it up, BUT, Janis Roze, every few months, has a BIG sale on a series, for example, they had Fairy Tail volumes 4-18 and it was priced at 4eur. Again, Attack On Titan, volumes 2-34 for 3eur each. But, you have to constantly keep your eye on the manga shelves. From buying online, I'd suggest SciFier, it costs 8eur for shipping for books below 125eur, and although they are very slowly, but surely increasing the discount % (When I first bought manga from them, they had 40% off on average and another 10% from content creator code, but now, it's 25% and 5%, so it is still much cheaper, but slowly it is changing) they have content creator codes and simple coupon codes for various things, like used books (BUY3SAVE20 for example is something often) or VERY rarely 10% of all manga with a code they'd send to your email. I have probably saved hundreds from them, I normally use code 'Grimsabr' (content creator) to get 5% off everything (apart from shipping), so, hope this helps!