Invest in DeFI, Or literally any good project. You'll never make your 6K back in time if you're just starting now. GPU, PSU, and other Hardware prices are through the roof. During Bullmarkets you DO NOT BUILD mining rigs. You buy the coin which will make you'll more money in a month than a mining rig will paying itself back. That's my personal opinion. I'm a big miner, but I started during the first bullmarket in 2017 and never stopped even during the bear market of 2018-20.

With ETH finally getting Phase 0 and moving to phase 1.5 in 2021/22 Personally game's over now. On top of that ASIC on ETH that are insanely powerful are coming online.