Buy a mining rig and you'll rarely (if ever) earn enough to pay back the cost of hardware.

Plus, you have to trust a hosting company to run it for you.

Assuming you want to mine at a profit, the easiest approach is to bid on future hashrate at auction - https://rigly.io

• Bid on hashrate per difficulty epoch
• Delivery to your pool account via stratum
• Payment held in on-chain escrow (multisig)

(Rigly is my project)