That's a great buy, and I'm sure the speakers themselves are as good or better than the Ventriloquist satellites. I can't comment on the Energy's - but Energy is a great mfg.
As for the sub, it's probably an average 10". Most well made 10" subs will run you $250 - $350. So again, that's a great deal on that system. I'd recommend though that you go demo that system before purchasing. Comments are just that, comments. Only your ears can judge if you really like the sound or not.
How big is your room?