I am in a very sticky situation, I agreed with a customer I'd do a job that takes 1.5 months for 25k$. The customer sells my job artifacts to a very reputable client and adding that client to my resume as a freelancer is excellent.
The problem is that after 1.5 months, the customer kept telling me to do these "little fixes and changes" so the outcome will be usable for the reputable client. The problem is that these little changes accumulated to an extra 3.5 months making the work I've done valued at 100k$. I've talked about this with the client, he's valuing my work at 75k$ and he is willing to pay 20k$ over a span of a year and another 30$k as 1% of useless stock options for a company he just opened that uses the product I developed.
He is older and has year of experience in negotiations and I basically just want to do my job and get paid. I didn't have a walk-away point and I just keep thinking maybe it's worth getting scammed if I atleast get SOME money and that reputable client. He also wants to hire me for 1 day a week for a year so that's 25k$ (which I work for but it's promised work)
He already licensed the product I developed to clients and we have 0 signed contracts between us. Only SOW documents and chats. So I technically have the upper hand but I'm afraid to use that advantage and think of getting on with my life, get scammed and enjoy some perks.
EDIT: he hasn't paid anything yet