Too much
The problem is that most of the other tablets are too close to the iPad in price. The iPad is still seen as the tablet to covet, so any competitors need to be coming in with something of similar quality but at a significantly lower price. Otherwise, most people are simply going to stick with what they've seen most of, and get an iPad.
Personally I'm tight and my 10" gen2 Hannspad with custom Rom is doing me just fine. For the princely sum of £127.49. As far as I can tell it does everything that a Tegra 2 based Fondle Slab should and I'm not even fussed about it being fatter than an iPad or that it only has an 8 hour battery life.