Just wanted to add a bit of follow-up and figured I'd do it here instead of editing. So I called a few property rights attourneys and they confirmed for me I was getting stiffed on the amount, but essentially said that the cost to hire them, plus get an appraisal, plus pay the appraiser to testify in court would wind up costing a lot of money.
I was told I probably should be paid somewhere between $7500 and $10,000, however good luck getting that without going to court, and if I did go to court that extra money would essentially all go to lawyer fees, court fees, and appraiser fees.
I did find a very nice attourney who spent a lot of time talking with me and gave me some tips in terms of how to negotiate for more money, gave me a bit of lingo to throw at the city such as proximity damages, in an effort to squeeze out a bit more money.
In the end I was able to get an extra $500 and essentially told be happy, most people are getting screwed over worse than you.
Sign the papers with a big F YOU on them. It's something, right?