So my question is: Is there a way to stake POSToken without paying those transaction fees that you get charged by mint function. I am used to classic wallet staking (for example DeepOnion coin, Gopnik coin...) where you just leave your wallet running and you receive interests for staking and you don't need to pay any transaction fees. I think this way of staking is better than mint staking.
Maybe I just need to wait more time and generate that mint function only once per month so I will not pay fees so often.
Firstly, always check calculator.postoken.org to check your amount of mined coins that you can claim.
Minting is not as expensive as you say. I use only 3 cents to mint by setting gas price in MEW to 1 gwei.
Infact I discovered a new thing has been added to MEW. You can now even set gas price to as low as 0.1 gwei!! I was surprised when I saw it. I guess this means we can now mint for less than 2 cents txn fees!!
https://bitcointalksearch.org/topic/m.23578056