Price: I paid 50 cents for the white and black case and $1.95 for the pink and black one so I can't argue here.
Value: The cases are doing their job especially at the price point I paid. The cases wrap the iPhone great and offer sturdy protection around all corners and edges for the front and back. And it maintains a semi-thin profile. It's not nearly as bulky as say an Otterbox case. I'd say it's a couple millimeters thinner on all sides than the Apple bumpers were on their sides. Hope that helps.
Quality: Here's where I wanted to knock the stars down a bit, but for the price I paid the quality is great. The quality is still great even if I paid up near $5 for these as they seem to be going at. Especially compared to the cases you pay $30 plus for at Best Buy etc. But a couple things to be aware of 1) It does not sit level on a flat surface. The phone rocks like the iPhone 3G did. I use mine on a desk a work a lot so that is annoying. 2) The white portion of the b/w case got dirty rather quickly. I used it two weeks with normal use and then heavier use one weekend and the white is essentially brown. (I wash my hands alot ;) ) The pink on the p/b case is of a glittery paint and does wear off as well, but will stay pink for the most part.