I think the Wii console that includes the Wii Sports game, 1 nunchuk and 1 Wii-remote is running about $250-300 locally. It will come w/ everything needed to get it hooked up (which just consists of plugging it into your tv and outlet - step by step instructions) and for one player.
You will need extra nunchuks and remotes (we bought two extra's of each, to make a total of 3, since there are there of us here). Nunchuks are about $19 and remotes are about $35.
We bought Wii Play (with 9 games on it) and it came with a remote. The remotes all came w/ "skins"...not colored. For that, I think we paid around $25-29.
We also bought a remote charging station (I think it was about $35 or so) because we didn't know how long the AA batteries would last in the remotes. I believe all the remotes, etc came with batteries.
The Wii Fit was $90 (89) and came w/ everything you needed to get it started (game, balance board, batteries, etc)...those are pretty hard to find right now though.
Shop new first...I went to some game stores and their "used" remotes, etc where only about $5 cheaper then brand new...and who knows if those have been thrown into the wall or something
Also, when you look at games...look at the back cover in the upper right corner....It will show a picture of the remote and a #, that means you will need let's say, 1 remote or if there is a #2, you can play two people, so two remotes needed....or if it shows a nunchuk, that is needed to play the game, so on......