Comments can come from a prewritten list or be generated per post. The choice affects both the bill and how long accounts survive.
Templates
Free and predictable: you know what will be written. The trouble is that so does everyone else. Identical text is the first marker by which both group moderators and Telegram separate automation from people. Thirty templates across a thousand comments means thirty repetitions of each.
The second drawback: a template does not answer the post. It fits any post, and therefore catches on nothing.
Generation
Every comment is unique and anchored on the post. No repetition, and a higher response rate — the reader sees an answer rather than a formality. You pay for it in model calls.
The drawback is unpredictability: a model can write badly, and reading the output early on is mandatory.
Which is actually cheaper
Templates are cheaper in direct spend and more expensive in attrition: identical text gets accounts restricted. Counting full cost including replacements, the comparison usually stops favouring templates.
The sensible middle
Generation with a tight prompt and an explicit ban on cliché phrases: it sets the frame and keeps the uniqueness. Fixing generic output is covered in the prompt piece.