Gotta be careful when making comparisons. When people refer to King West, the neighbourhood, they're referring to Spadina to almost Dufferin, or Shaw where DNA3 is. You can't compare DNA3 at King & Shaw to Festival Tower at King & John. Not that you are, but Festival Tower isn't a comp and shouldn't be considered in this case.
Was the $370,700 before or after the 3% discount? $595 or $578 psf w/o parking is too high even with the large balcony. If that's before the 3%, add $35K for parking and you're looking at $634 psf. If after, then that's $652 psf (plus over $400K re: HST and land transfer tax)
If pre-construction for most condos in King West is $600-700 psf without parking then by that standard he is getting a good deal. But I don't think so. Anyone buying there at those prices had better be in for the long haul. King West will grow, develop, and become an epicentre of Toronto. So over the long term, if these are the going rates for King West and people who buy today live in them over the course of time, they'll be just fine.