I think Ahab's inquiry was two engines for $30,000, but I agree that the the first reply seems to be for one engine. The new price seems way too low for two engines, but I'm confused because the overhaul price seems high for one engine and pretty aggressive for two engines.
So I contacted Certified Engines and got a quote of $21,500 ($24,800 with new cylinders) for one engine (including magnetos, harness, spark plugs, fuel injection system, fuel pump, starter, alternator, oil cooler, and a new logbook, but with the usual caveats, including a serviceable crankcase and VAR crank, warranty may be seen at
www.certifiedengines.com). I think a $15,000 overhaul may be possible with a qualified mechanic (not a shop) and perhaps skipping some accessories (e.g., starter).
Ernie