Past performance is not indicative of future results.

The reason the price on rigs was rising was because the bitcoin price rose much faster than the hashrate, and the ASIC manufacturers simply have not been meeting demand. As deliveries from the manufacturers continue, hashrate has been increasing faster than the bitcoin price -- resulting in lower profits for the miners. If that continues, entire generations of older, lower-performing ASIC hardware will be decommissioned. Newer rigs could hold their value, but appreciation in value in that environment is quite unlikely -- especially with halving coming up in a couple years again. The biggest unknown is the future price of bitcoin. If it approaches $100K, then the existing equipment would likely hold acquisition value, and increase above that. If it hangs at the sub-$50K level, the halving will be brutal for the mining industry.