you just bought a car and they tell you there's something wrong as you pick it up?huh?if that was me i'd tell them to cover it-at the very least they could cover the labour or parts.$600 is fair.my acura needed a new belt and pump and that's what iwas quoted 6 yrs ago.
try this site:
'95 s500 (bought for wife but can't bear to share!!!) 125kms
'92 legend 180kms
'88 tbirdturbo(fantastic car-only regular maint.)120kms
'87 mustang gt(gone)
'85 mustang gt(gone-but not forgotten)