Rent an email list from a guy like this and you’ll be forever known as a spammer.
Why? Because there is no way all these thousands of people gave him permission resell their email, again and again, to anyone.
Have you? Would you? No way. So if someone like this claims to have some sort of email permission, it was acquired deceptively.
Which means that if you rent the list and send email to it, you get flagged as a spammer, because ISP spam filters recognize the set of names on the list. And you are, in fact, a spammer, because the recipients never gave you permission to email them.
Guess what happens next — all of your other email gets blocked by the spam filters, too.
What would it do to your business to have 5%, 10% or 50% of your email never delivered?