Facebook Rental Reply Bot

I run a car-rental page and I’m wasting too much time manually answering “How much?” on public posts. I’d like a small bot that monitors specific Facebook posts in other groups or ad comment threads and... (Budget: £20 - £250 GBP, Jobs: API Development, Automation, C# Programming, Facebook API, JavaScript, Node.js, PHP, Python, Software Architecture, Web Scraping)