1) Not until Android gets a lot better in terms of available apps and the interface for its tablets. $300 is too much for the Acer Iconia A100, which specs-wise is pretty similar to the Galaxy Tab 7" Plus.
2) Never. They price their products at a premium as they expect people to see them in the same way that people see iPads. And $350 is high; too high, really. Android, as it stands in the tablet market, can't beat the iPad in terms of the app ecosystem (there's a lot of crap in iOS-land, but a lot of good apps too) or ease-of-use at the moment. Look at how often you may have to reboot a Kobo Vox, and that's using the more STABLE version of Android (Gingerbread). Google doesn't have the will to assert its standards with either the hardware makers or the telecom companies which keep forcing Android onto sub-standard hardware or lock it down so heavily that you can't do anything with it. Or else they won't enforce a common standard which means that the $9.99 game you bought on one tablet will work on another... even though they share the same CPU, RAM, and OS.