I had exactly this experience many many years ago when I was just starting out. I'd written a small tool that enabled pop-up messages between [Windows] users on a network. It was protocol agnostic - as long as the users had a shared file area, it would work. This was back in the day when even internal email was new and mostly non-existent in the workplace.
I sold it as shareware originally, but then a Big Fish came along and said 'we want a licence for 1,000+ users, but can you come in and meet us to discuss'.
Seeing this as a pivotal moment in my entrepreneurial career, I agreed to meet them.
Five minutes into the meeting they started rattling off a long list of features they would like added (for no extra fee). Somewhat shocked, I numbly agreed in principle that I'd look at implementing them for the next release.
Once I had time to think about it, I realised that as a one-man-startup there was no way I could implement their requests, and had to back out of the deal.
And that's the problem. The people with money assume they can ask for whatever they like and have no concept that sometimes it's simply unprofitable for the little-guy to deliver it.
"The people with money assume they can ask for whatever they like and have no concept that sometimes it's simply unprofitable for the little-guy to deliver it."
Thats a question of negotiating, isn't it?
They can ask for whatever they like and you can reply with whatever you like.
And then you find a agreement, or not.
The problem in your case seems to have been more lack of confidence and experience on your part, because like you said, selling a licence for a existing product is something very different, from making a contract about new features.
Otherwise a little guy can grow and hire more people to help him with a big contract, if this is what he or she wants.
