As expensive as this is, it's a need. Kids need to be able to take the calculators home so they can complete their homework. And it's not just for math class: if the student is taking college-prep science, the calculator's a necessity there too.
Last year (when my daughter was a high school freshman) I asked a math teacher to recommend a calculator that "would last" my daughter through high school (and hopefully college), and she told me to buy the TI-84 Plus Silver edition. I didn't mind spending the money on it, BUT I didn't want to have to replace it with a slightly better version in another year or two. My math teacher friend assured me that this calculator will be the last one I'll have to buy for her.
Staples offered the calculator on sale at $99.
I took their sale ad to Office Max (because they price match), and I used a $25 off a $100 purchase coupon, bringing the price down to $74.
I used my Office Max teacher card, and I received an $11 rewards check from Office Max later in the year. Because I also bought other items, I can't say just how much "came from" the calculator purchase.
Suggestions that have nothing to do with money:
This calculator is easy to find in gray and black. Hot pink is also fairly easy to find. Try to get another color; it'll make your student's calculator stand out, and it'll prevent friends from ACCIDENTALLY taking it when they're all working together.
If you can't locate one of the cool orange or lime green versions, look for a face sticker, which -- again -- will personalize the expensive item and make it a little harder to mistake in a crowd.
Regardless, engrave the student's name on the cover AND on the inside of the battery cover. This'll help the student prove ownership if the calculator should suffer more than an accidental walking away.