wow..are you sure they did all the parts? normally engine balancing means to rebalance all the engine moving parts. to achieve that, some lightening are needed. BUT the result can only obtain by changing new bearing,seal, ring etc..if not, the balancing job is so much difficult.
you know la...our g13b is very old. even it's a reliable engine, mechanical material in it has a wear and tear. normal high speed bearing also only last for several years...5 years perhaps.they tend to wobbling and gave much friction to the engine motion and end up with higher engine load.to get maximum of balancing job done, all bearing, ring, seal must be changing first. off course they must clean up the whole engine. then change the piston/ring.,new set of valve needed (grind, skeem head if necessary) to get max compression. once done, balancing job started by rebalance the crankshaft..you will see a better balancing result. then the Camshaft and lastly the flywheel..(9-10 lbs) not to forget the general overhaul gasket from SGP only.
fuhhh..i would estimate around rm2k - 3k.
the result will impress you much better. the cost will be pay back after a while cause you FC will drop.
anyway, lets ask the guy..maybe he know more about this.