93SC - prices from RockAuto
$238.74 - 6 pistons SEALED POWER Part # H675CP {#H675P} (Available 0 to 1mm oversized)
$387.89 - Re-Ring Kit, includes piston rings, rod and main bearings, and gasket set, valve stem seals. SEALED POWER Part # 2056339M Includes Gasket Set. Gasket set includes head, intake, front cover, water pump, valve cover, exhaust, and throttle body and intake plenum gaskets.
$24.14 - 2 sets of head bolts FEL-PRO Part # ES72131
$32.99 - timing Set CLOYES Part # C3086K Includes: Cam, Crank, Chain
$683.76 in basic parts assuming heads are ok.
$425.00 Labor to remove the motor, and break it all down, figure 4-5 hours at a labor rate of $85/hour (this isn't skilled work)
$500.00 Machining costs. Soak the block and heads. Pressure check the heads, surface the heads, clean up the block, resize the rods, etc...
$300 to assemble the motor figure 3 hours at $100/hour
$595 Re install the motor, button it up, test drive. figure 7 hours.
So that is $2503.76. Round it up for $3000. At $5000, they are telling you that they don't want to do the work. Personally I'd track down a machine shop that can do the machining, and see if they know someone that can do the work. They may have a line on someone willing to be more reasonable.