Im currently doing around 400€~ per month from monero mining which is perfectly fine for me, but how does it look in the future? I know its hard to predict it, but is there any way to get an estimate amount i would earn in 1 year with the same hashrate? 50% less or even more?
That's probably good rate I have seen until now. You must be having higher versions of GPU installed. That's really good one and monero looks just fine to me for the next year. It's one of the first preferred currency to be mined with gpu after the zcash. The mega altcoin miners like HashNest, minergate will also provide you the best algorithm for the Monero only becuase the difficulty level is really optimum for it. Let's hope it stays like that way for next year or so and it will.