I saw this article in edweek.org and have been sitting on it for awhile: District nixes cash-for-grades fundraiser. A middle school was offering 20 points of test credit for a $20 donation. People got up in arms and they had to cancel it.
The cynic in me says that middle school was just cutting out the middle man. The obvious parallels are teachers who give out extra credit for bringing in boxes of Kleenex or school supplies. It infiltrates our grades in other ways too. We're doing a canned food drive at our school and some teachers are also giving out extra credit for bringing cans. Some families can afford to donate cans while some cannot. How about extra credit for bringing a parent to back to school night? In general, middle or upper class families are less likely to have to work at night.
In the end, when anything but grades reflect any mishmash of values this is what we end up with. In standards-based assessment, the achievement scores are reported and all that other stuff (work habits, participation, behavior, etc) is separated out.