A and C - please tell me you have forgotten to put a decimal point in between the 1 and the 8 of those figures!!
The Rotax 912A is an 80/100 hp certified, 4-cylinder, four-stroke engine, while the 582 is 65 hp, uncertified, two-stroke engine, so you can't compare the overhaul/replacement costs.
Moreover, I think authorized local service centers can also remanufacture/overhaul a Rotax engine and you don't need to send them all the way back to Austria for that.