Ooooh, you save a whole penny! So what, it's just so if you wanna buy a lot then you don't have to go through the whole process 5 times. Besides, the price for Microsoft Points is the same (500 for $6.25, 1000 for $12.50, etc.) and the price for Xbox Live is the same price every month, no matter the bulk buying. Unless you buy a year's subscription starter kit thingy. Who cares.
Also, what if your Wiimote breaks (and it's all your fault so you can't return it), would you want to pay an extra $20 for an extra nunchuck you won't even use?
Yes, there is tax, you have to tell them what county you live in so they can apply it....though you could just say you live in Oregon...get your points off the online store through your wii and the prices make more sense.
and no tax!