I think it is a waste to cancel everything out. Can I at least pay you half the money?
I am sure you already have made a lot of progress, and this is definitely worth $100. So I create a new milestone for this amount. Do you think you could send me what you already have? (Your perl script and the files you processed)
If ever you change mind and feel you can have even only 50% match, I would be most happy to pay you $200: we already have been so close from getting this done!
I look forward to speaking to you, I hope you agree with this.