What part of "parameters don't stay constant do you guys not get?"
When I bought them at 10000 USD, profitability/miner was about 260000 USD
One month later, difficulty increase, and profitability/miner was about 60000 USD
Ages later, once innosilicon had enough mining with my miners and sent them to me, difficulty increase, and profitability/miner was about 6000 USD
Innosilicon had also a few surprises for me (hashboards burn) some miners not working etc. etc.
Today, you can see the profitablity yourself
BITMAIN are now flooding the S9 just like they did with the D3 cuz the new Halong miner will ship soon
ASIC is destroyed
Ethereum will switch to POS
GPU Destroyed
Save yourselves and buy godamn crypto and let the ASIC producers lose money and be left holding worthless hardware for once
Can't say no one warned you guys

I mention similar things a few times before. Pls do your own due dilligence before u guys purchase.
Juz look at mining difficulty. It was 0.1 in jan and 1.4 in december. From dec to feb, it moved from 1.4 to 2.8. Yes, it increased by more than 11 months worth of difficulty in just 2 months.
For dash, it has become unprofitable for D3 miners. Some plug it out and difficulty went down. It will go back up as dash price increases. So, bare that in mind too and do your own due dilligence.