For a number of years I have been running a small tool I made for a very keen and dedicated niche(that is expanding) and this tool became an important part of this ecosystem.
During the last year I have been working on an update to my tool and it has recently entered beta phase. It has been received very well from the users.
I work on this as a side-project and don't generate any revenue currently, while in beta I have a paid plan for free, which already has ~50 members I could convert to a ~10$/month subscription.
Recently, I had a VC-backed company that works in the same niche approach me saying that's be interested in a partnership. The kind of like "we put your tool on our website and pay you some money".
Yesterday I had yet another big company(50+ employees, VC-backed) approach me asking about a similar partnership.
These are legit players in this field and it feels surreal that they are approaching me.
But I have no idea what to ask for. This being a side-project I'd be happy to make any money whatsoever, but I feel like this is actually a real opportunity to maybe start a small business.
I don't really live in a place that has a startup community and I don't have any experience with any of this myself.
How can I learn how to value my product to make sure I don't undercut myself but don't squander this opportunity?
Thank you!
Edit: as a rock-bottom baseline, try to figure out how much time and money you've spent on this and use a rate like $150-200/hr to get a bottom number, assuming you'd have no further involvement. If they want you to commit to future involvement, it's more of course.