The offer is only realistic if it is an account and username of a very famous person that means at the end, using this account for scamming possibly brings bigger successful scam money that significantly exceeds the initial cost of $8,000.

Otherwise, such offers can be considered as too good to be true offers and if you are aware of your reputation and possible value of your account, you will easily recognize this offer is scam.

Report that account first.
https://telegram.org/faq#q-there-39s-illegal-content-on-telegram-how-do-i-take-it-down

If you are curious, you can check that account one week or several months later, you will see it with a Scam tag or it will turn to be a Deleted Account.