You won't actually buy the machine as stated in the website. That is misleading because you don't physically own it. I doubt that they will even give you any document proving your ownership. They control the machine while you pay for whatever service they charge you.
Another thing, I would stay away from any platform that offers cloud mining service.
Wasn't that what Genesis Mining was doing? They'd sell you a lifetime mining contract and after a year send you an email that due to difficulty change your contract is no longer profitable and will be closed. At least they had real miners but they were cheaters in their own way.
Referral codes are normal in this business.
If you read some of the reviews you'll see that most of these people were doing staking with them which is much cheaper and can realy be done with just a few dollars worth of altcoins that you can get for free from various airdrops and campaigns.
It's also easy for the company to run a legit staking business because they don't need any hardware to do it.
I really doubt that they have a real hardware mining facility and that you will get what you pay for if you buy one of those 2000 dollar antminers.