This is why there are so many miners now.
This may seem obvious to many but I'll mention this again as many people seem to forget about the difference the between break even point and reaching full ROI.
With mining rigs, you have two important metrics. You have the break-even point (the point in which you've mine enough Ether/Zec/LBRY etc and convert back to fiat) where if everything went to pot, you could sell (or repurpose) the hardware and not take a loss. I use a 50% metric for this. So if you spent 2K on mining gear, you only need to generate 1K in crypto to safely unload the rest of your gear and still break even.
The second metric is paying off the entire rig after accounting for power costs etc. Currently, this takes a lot longer but is still achievable if, or more likely when Ether/BTC climbs in value. This is the ideal goal (and anything after a full ROI turns your miner into a digital representation of a money tree provided your power costs are average) of many miners but you only need to hit the first metric (break even) to not take any loss (other than time invested which is variable and also beneficial as you'll learn a few things).
Happy mining all.