For mining researchers.
If you want to start mining on ASICs, then try renting an ASIC for a few days. Usually you will pay more than you will ultimately earn from mining, but you will get an understanding of the real profit.
Renting ASIC units on mining rentals is very expensive and the hashrate they provide is not stable.
Are you pointing to real profit? I don't see a real profit from renting ASIC units but if you talking about holding your mine coins to make a profit there's no difference between buying Bitcoins and holding them for the long term.
Or if you have a budget and have a cheap power source buying your own ASIC units is way better.