So, I talked to the user that is mentioned in the group that @lil17th is allegedly selling (Tg username that is mentioned is @lil17_th) and this is how it went.
By the looks of it, it might be a legit Telegram channel sale, but even if this is not a classic scam, there is a catch; its very easy and cheap to fill Telegram channel with hundreds of thousands of bots and to make channel even more legit there are services that will give you fake views meaning even if everything goes well and you get the group, most likely it will be completely worthless for any sort of business. Not a bad business model when you think about it, to spend few hundreds of dollars on building up the channel and then selling it for a couple of thousands.