[mario0b1]

But this then brings the question back (atleast for me): What happens when all coins are mined? I just looked it up and it's already >80% mined. So if miners would leave the pool and then suddenly (suddenly might even be a long period of time here, I don't know to much about bitcoin) all coins are gone. What happens?

Edit: What just got to my mind is that we will never gain more bitcoins then those 21 million, but we surely will lose them (people lose they keys, die, whatever). Will the price go up to "infinity" or will it suddenly drop to 0?

[berbec]

According to [1], in 2140 each block will give 0.00000042 BTC (big guess based on mining trends). The reward per block goes down as the number of remaining coins reduces.

This introduces a very unstable system. If the price of bitcoin doesn't (double + increase with inflation), as the block reward shrinks, the rewards will become useless.

1: https://bitcoin.stackexchange.com/questions/10486/when-will-...

[sauwan]

Theoretically, transaction costs (will) pay the miners.