Ok, I've done more research and have a couple questions. First off, I've decided to go with the Arduino Due purely for performance reasons after seeing some benchmark tests on youtube. So there's that. But when looking for lcd's shields for arduino, i noticed there are kits available for ~$145 like this one from 4D that come with the lcd and accompanying shield:
http://www.4dsystems.com.au/product/uLCD_43_PT_AR/
But on ebay, you can buy a cheap display and then a seperate shield from china ALL for less than $30 and they are said to be arduino compatible. Any reason for the huge price gap and anything I should be careful of when piecing together the parts i need?