Buyers didn't show to closing, breach of contract

[Matt Lopez]

Under contract for 410. Duplex appraised 380 (super ****ing low ball) brings in an estimated 3,900 a month in rents. 
buyer agreed and SIGNED addendum to purchase at 397,500. 
day of closing they dont show, tell us they didnt know what they agreed to pay over appraised value and are trying to get us to accept 386k. 
my agent had me lock in our month to month long term tenant to a year lease for THEIR lender and now they pull this.. 

they have only 5k in escrow account.. 

my agent wont reduce his commission from 3%-2% to help bridge the gap. 
suggestions?? 
Retain a lawyer and sue for damages? 
PLEASE HELP