I don't have any experience with that site, but my little digging around bring me to a conclusion that it's not a site or mining equipment reseller to trust.
They are liars. Very dishonest. You can never trust a liar.
1. Claim to have been in business since 2018 and selling 200K miners since 2021
The domain name however is not more than 5 months old. That probably the time they bought it
Domain: bitmars.io
Registrar: GoDaddy.com, LLC
Registered On: 2023-05-22
Expires On: 2025-05-22
Updated On: 2023-08-19
2. Someone already complaining about them on Twitter
Be careful with this company. They are not honest. They do not honor their quotes.