Trying to step back a bit and look at the OP's scenario in a more general way. If I were facing a similar situation, I'd set a target purchase price, say $800. That will purchase a mid to high level iPad. (Yes, one can spend less but $800 USD seems a reasonable estimate.) Add another $100 for accessories like a bluetooth keyboard.
Now compare the functionality that $900 purchases in other products. For $900 one can purchase much greater processing power, much more storage, a larger and better screen, true multitasking, greater expandability, simpler integration with other devices, etc. etc. etc.
On the other hand, the iPad is somewhat more portable, has a longer battery life... 1.5 lbs versus 3 lbs and 10 hours versus 4-5 and unlike the alternatives it has a touch interface.
Another way to look at it is to imagine that the iPad were the standard of what is considered to be a "portable computer" when new devices with more processing power, more powerful software, more storage, larger and better screens, true multitasking, multiple resizable windows, and greater expandability are introduced to the market. How many would jump to such notebooks at the price of an iPad?
The iPad is delightful device. It's new and shiny. Its functionality can be stretched to accomplish tasks that few if any other tablets can match and that functionality can nearly match that of a budget notebook. But it is very difficult to justify in terms of functionality per dollar.