The Prius holds it's value to some point. I was reading an article on used Prius's selling for higher than their suppose to be, I found that to be interesting and funny thing is people still bought them. The demand for the Prius is strong and some people are willing to pay for it cause of how much they trust the Toyota brand, can't blame them.
The dealers can only push the Prius price up so much until it's not worth the buy.
I also think the Japan Tsunami and Earthquake played a roll in the rise in Prius prices.