I am sorry to hear about the problem.
$4500 is a LOT of money to repair the engine's bearings and crank. Are you getting an entire rebuild? If you are the dealer can always claim you are going above and beyond the repairs necessary and are getting a full rebuild, to which he may claim you are not entitled. You may just be awarded the bearing and crank portion of the rebuild.
IMO unless you are certain to win, shop around. $4500 is about twice what you need to spend.
Good Luck.
