This page is for someone who intends to resell Telegram services: open a panel, set their own prices and take orders from other people's channels. If you are trying to grow a channel of your own, that is a different job, and the walkthrough for channel owners lives in our blog - it covers what a subscriber actually costs and how not to burn your reach.
For a reseller Telegram is easier than most platforms for one reason: an order is tied to a public link to a channel or a post, not to an account with a login. Your customer hands over nothing, the «I changed my password and it all stopped» dispute never happens, and the result is visible to them in the counter under the post. Refund rates are lower here than on services that need access.
The second reason is catalogue depth. Providers keep dozens of variants of the same Telegram member service: different geo, different periods during which members are not dropped, Premium accounts listed separately. This is the rare case where your markup does not have to be a flat «plus 30% on everything» - buyers choose by guarantee length, not by your price per thousand.