the system was more reasonably priced at $250 , compared to PS3 at the time which was going for $400-$500
Parents are looking at upwards of $400 cost just for the deluxe system and 1 additional game or even if they go with the basic for the kids they will still spend close to $400 with just the basic system + 1 game+ tax
Although the price does seem considerably higher than the Wii launch, keep in mind that all of the Wii remotes, nunchucks, CC / CC pros will be compatible and still be used as the primary input source with the Wii U (barring the Wii U CC Pro). Assuming you already have those, that alone can save $50-$100 at launch compared to not only the original Wii launch, but any major console release.
As for additional games, Nintendoland is looking at least two times more robust than Wii Sports was, so that game alone, along with the Wii backward compatibility, should be enough to entertain for at least a month until Christmas.
So assuming the average console consumer has at least one or two sets of wii remotes and nunchucks (which is fair if this is a family upgrade purchase), The $350 plus tax route is very similar in pricing to the original Wii launch ($250) plus extra Wii remote ($50) plus possible nunchuck ($20), a $30-50 dollar difference is not very significant, especially if you consider that the launches are six years apart, some inflation can account for that.
The external hard drive will be an additional cost, but its safe to say you can wait some time after launch before it would become a necessity, and can get one on the cheap / already have one anyways.