So I'm wondering if there truly are account sellers. Or even buyers! Is this a liquid market?
I've seen threads where accounts where accused of being bought and tagged because members found that there is enough evidence that the account is no longer handled by the original owner of the account and I've seen someone admitting that they bought the account.
How much would someone pay on average for a M/Full M/Sr. M/Hero M/L account?
I don't think anyone really knows, as you have said, the offers you saw looked like scams.