@Mason Clark It's not clear if your offer is in writing or just verbally? If it's verbal, you don't have anything to worry about.
And, if they are in writing, I'm sure there are contingencies that you can back-out of.
@Mason Clark Then tell them you will have to lower your offer or walk away. Don't sweat it, just tell them the financial picture changed the #'s.
Plug the numbers into this pro forma to see what your real profit will be. Income and expenses magically change once you see them in writing. I just got an income report from an owner who lives in his multifamily property and he recorded $9000 in rent from his own apartment that he lives in! lol...is he really renting his own apartment to himself and paying himself rent? Interestingly, he was renting his own apartment to himself for a really high rent, higher than any other rent in the building! Easy come, easy go, there will be another one...