simple chatbots for a social media channel. No programming necessary. Setup in tools like Chatfuel or Manychat. Costs: up to approx. 1 - 2.000 Euro.
simple chatbots with integrations. The same as above, but with a few additional features such as linking to Google Maps or iCal. No programming necessary. Costs: up to approx. 2 - 3000 Euro
chatbots with their own individual backend. Programming would be necessary this time. Typically part of an existing system, integration into an existing database necessary. Such chatbots would cost up to 10.000 Euro.
individual chatbots with complex integrations. This solution would be like point 3, but in addition API integrations come in different systems, like ERP, CRM etc. Here the Bot costs would reach already the range 11.000-20.000 Euro.
AI-based system. This would be the first alternative in our list that works with a "real" AI and provides "intelligent" answers. The backend would be one of the chatbot frameworks, like the mentioned Azure Bot Service from Microsoft. Typically, several dozen questions are automated in such frameworks. The chatbot costs in this case start at 20.000 Euro and can easily double.
The combination of points 4 and 5, i.e. AI-based system with numerous integrations. Here the budget can reach 100.000 Euro and more.