Product "Rebates"

So, last night, we got a new cell phone for Steph. She had been using the original one that she got when we first got service for her back in 2001. We got the phone from Radio Shack because the people at the Sprint store have been very un-helpful in the past. The phone was $200 with a $170 mail in rebate. I've never been too wild about the whole rebate thing, but now I'm REALLY not wild about it. I guess all the other stuff I've bought with a rebate was over the internet (think: no sales tax), but when I pay 7.5% sales tax on a $200 phone, well you get the picture ($15). So, the phone that they advertize as being "$30 after mail in rebate" actually winds up being $45.