Used 8700's are running from $50 to $150 or more on eBay. I hope the price of the 8700 DOESN'T drop! Mine is in excellent condition, so I might be able to move to an 8100 for $50.
I'm waiting to hear what the performance is like compared to an 8700 though. If the phone is no better, and the device is significantly slower than an 8700, not sure if I could be persuaded. However, if the phone is significantly better, and/or the speed is at least close to an 8700, it's very tempting...