I would have to recommend in this situation that you contact an attorney. A real estate agent can do a comparative market analysis on your home. An appraiser can do a full appraisal, but I still think you would want legal representation for this type of situation. I can't tell you if a legal aid office would help with this situation if you are concerned about the expense, but I do think it is probably in your best interest to at least consult an attorney who specializes in real estate.

I can tell you generally what the laws are, but you really should have a legal advocate on your side so that everything is done correctly. I don't know what firm represents the school you are talking about, but this firm would not be able to represent you. A good source of an attorney referral would be the mortgage lender at your bank. Each bank uses a real estate attorney to prepare mortgage documents, they can recommend someone to talk to who can refer you on if the case needs more expertise than that particular attorney feels they have.