"Put the same bot on WhatsApp and Telegram too" sounds like a configuration change. It is not a hard project either — but the parts that differ are not the parts people expect.
The first version of almost every B2B tool is single-tenant by accident. You build it for one customer, it works, a second customer arrives, and you add a customerid column.
"How much will this cost to run?" is the question I get before any technical one, and the honest first answer is annoying: less than you fear, in a shape you did not expect.
A support chatbot that makes things up is worse than no chatbot. A missing answer costs you one email. A confidently wrong answer about a refund policy costs you an argument, and the customer has a screenshot.