Prices of all tablets have been artificially blown the past years, so much, that we kind of got used to their higher price!
The first eeepc netbooks had a starting price aimed for the $200, and a street price of $300.
They had processors based on 65nm technology. Current Atom technology is based on half that size; meaning it performs almost twice as fast, while still maintaining it's low power profile.
It also means that the smaller manufacturing results in cheaper chips!
They've been selling those chips (terga, intel Atom) much higher in the beginning, but once the price of those chips drops to an acceptable level, we will see the tablet prices falling for another $150 (even a tegra 3 tablet, at the end of it's slope, can be sold for $200 with profit!)