POW doesn't end in July, only the miner rewards will be less. Nobody knows how the profitability will be back then. Even right now an entire week can make all the difference. A week ago we were at $1300 and now we are at $1800 again. Price is very volatile and the difficulty keeps climbing.

In my opinion I wouldn't buy 3500 Euro because its like $4200 USD for a rig which has GPUs which are 5 years old. At $4200 that's about $700 for a GPU. The motherboard, PSU, cpu, ram don't really account for much. So lets say $600 a GPU. That is crazy expensive since this GPU when new was $250.

So when the mining fad is over and you want to liquidate your GPUs, you won't get much in the second hand market. I think they were going on Craiglist for $120 before Covid and before Ethereum starting to pump. I wouldn't buy that rig.