Bad logic is bad. I don't care how much this thing looks like an iPad, it DEFINITELY isn't. It runs on Linux, which the developers don't have to pay a cent for. Compare this to the iPad, which runs on iOS, and costed Apple actual money to develop. Also consider build quality (doubt the screen is as nice, for example), parts used (I can damn near guarantee this thing isn't anywhere near as powerful as the iPad, but with no spec list it's hard to say exactly), etc. The iPad is loaded up with a TON of Apple-developed software, depending on the version you get it has 3G and GPS, multi-touch screen, etc. Also, keep in mind that the iPad is to be sold at a profit, not to break even, because Apple's not trying to go out of business.
In other words, this is a very flawed comparison, and in no way a decent example of this so-called "Apple tax". Try again when you find a product that's actually a close equivalent.