I grossly under estimated my costs for a job and want to renegotiate compensation. Should I?

Question

I've been self employed providing data collection/analysis services for two years and landed my biggest client, a bank, about two months ago.

I agreed to collect, clean and tag 10,000 (public domain) mortgage contracts that would basically give them a map of every loan that's been issued for every commercial building in their tri-county region for the last 10 years. Said bank will use this data to reach out to business owners who's loans are coming up for refinancing (loans from other banks) so they could get the business to refinance with them. If my client signs on 10 - 20 new loans in the next 5 years using my database they could easily make an additional $1,000,000 in revenue in the next 10 - 15 years.

I thought I could get the job done in a month so I asked for 2 months. They agreed but decided last minute they only wanted to pay once the job was completed. I agreed to this (mistake No 1?). One strange thing is that I never signed an NDA.

As of today I'm three weeks behind on my original delivery date (of which they seem okay with). I'm almost done but I've realized I've sold myself really short because by the time I'm done/paid the amount of unanticipated extra work I had to do is going to dilute my effective hourly rate to a fifth my market value (since I also racked up out of pocket costs for additional labor).

Short of my written agreement with said client I literally owe them nothing. Since I don't get paid until I give them the database there's nothing really forcing me to stick to the (unfair) agreement I naively made (except morals). What's more I now have a list of at least 30 other banks I could potentially sell this data to.

Is it in bad taste to try to renegotiate for higher compensation? Do I risk loosing their trust in my business as one that "keeps its word" if I do that? What should I do?

UPDATE

I decided to resist renegotiating any prior terms and stayed true to my original agreement. I felt this was the right thing to do. I've learned a lot from this experience:

1. Resist the temptation to use fixed price contracts for work you've never done before. Such instruments are better suited to familiar tasks you've actually done before where the costs are already known.
2. Focus on and deliver the lowest hanging fruit first. One of the reasons costs ran away from me on this project was because I was being a perfectionist and wanted to give my client the absolute best product I could. That's a nice goal but perfectionism is costly and sometimes (often?) is down right infeasible (as was my case). Turns out I could have finished this project 4 weeks earlier as the client was satisfied with the "imperfect" (by my standards) product.
3. It's better to reach out for guidance/help from your support community (be that SO, your friends, family) regularly and as you face challenge. I wish I had consulted a trusted friend about this problem sooner as that would've given me a fresh, calm person's perspective on the problem.

I hope my documented experience here is useful for someone.

Answer 1

No matter how you present it, that is blackmail. And I very much doubt a bank did not let you sign an NDA which prohibits you from using this data elsewhere.

Fixed price is exactly what the name implies: fixed price.

What you can do is create an overview of the work and costs and propose a new compensation, while not in any way holding back on delivering what you promised. If you're lucky they be willing to compensate, if you're not lucky you can take this lesson to the next project.

Answer 2

Since I don't get paid until I give them the database there's nothing really forcing me to stick to the (unfair) agreement I naively made (except morals)

Not true. If your client has made any commitments based on expectation that you'll finish, and you don't, you can be held liable for any damages your client incurs as a result. The term for what I'm explaining is called 'reasonable reliance'.

It would be poor taste to try and renegotiate. It's bad enough that you're late as-is, but attempting to renegotiate is pretty much a guarantee that you can't use this client as a reference AND you're not going to see any repeat business. You're going to have to suck it up, unfortunately. Hopefully your estimating skills will improve as a result of finishing this gig.

One last thing. As for the NDA - you're using publicly available material. Not sure how that's relevant. With the same skill set as you, anyone could derive the same results. According to this, you may have an implied copyright in the work-product unless your contract specifies otherwise, so maybe that's a bonus. But non-disclosure and copyright aren't really related concepts.