Also, your remote cost is WAY off. $40 per remote. So $120 for three. Then if you want the nunchuck for each one as well that is $20 a piece, so now it is $180 total. Oh, and if you want to play any VC games you might need a classic controller for another $20, and since you will likely want/need two that brings your price to $220.
So, now we are looking at $470 overall, and you have yet to buy a game. The Wii is only the cheaper machine if you are not wanting to turn it into the party game machine it is designed to be. I will give it credit for allowing friends to bring their own remotes and sync them up as a guest and then allowing them to use their own Mii that is stored on the remote.
The PS3 owners that are popping up in this thread will very likely call me a Nintendo fanboy for this, but that isn't quite right.
Yes, it's $40 for a Wiimote and $20 per nunchuck, but considering that adds up to the equivalent of one 360 controller ($60) and just $10 more than the rumbleless SIXAXIS, not to mention the fact that you rarely need two Wiimote-Nunchuck pairs at a time, much less four, the cost is roughly the same for all systems.
On the other hand, the Virtual Console point is valid because not everyone owns Gamecube controllers (supported by nearly every VC game), and because the wireless (though awkwardly tethered to the Wiimote) Classic Controller doesn't cost much more than a Gamecube controller these days.
Still, implying that you "have" to pay $400+ on a Wii before getting a game is a tad unfair. Although it generally makes a good party machine, as you said, the best games that have been released on it so far have all been single-player or with limited multiplayer (Metroid and UR MR GAY, for example). By comparison, a lot of the "party games" (especially third-party ones) so far are half-assed trash (Mario and Sonic Go to the Olympic Games, for example).
It's kinda like saying a 360 "must" be bought with the HDDVD drive to be even slightly comparable to the PS3. I guarantee you that if I were to buy a PS3, its ability to play BluRay movies would go 100% unused.