Hi,
in Germany the stamps are quite cheap. Domestic postcard 0,70€, domestic letter 0,85€. An international postcard costs 0,95€ an international letter 1,10€. when it comes to special sizes it can get expensive though. When you get over the regular 20g per letter the price increases to 1,70€ international and 1,45€ (I am not sure about that last price) for domestic letters. The Deutsche Post is very strict on the weight. So if you put too many stickers on the envelope, you better check the weight twice!
I never realised these forever stamps, even though I already got a lot of lettersor cards from US… here in Germany you have to buy additional postage every other year. This is why we have all kinds of stamps with postages that noone really needs, like 0,80€ where you need 0,85 for a letter. Or 0,02€ – you could fill the whole envelope with stamps!
have you ever noticed, how different the stamp sizes are? Sometimes it is almost impossible to put everything on the envelope – address, return address, stamp, additional postage stamp, priority sticker…