Lurker here, been watching your work on this. Good stuff! this is a construction modification(aka change order) Since these are mods 6 & 7, there will be an original contract and mods 1,2,3,4,5. if you track those down, you should be able to confirm the historical $, under this contract and determine if error or something fishy. Agree it looks way off though.
Construction acct / admin anon