It isn't just the retina display. It's also the standard 8GB RAM and 256GB SSD.
The Retina MBP starts at $1,999 with Education discount. $1,999 + $100 B2S Promo is very fair for it, considering that it also COMES with an SSD. The non-retina MBP has an HDD. This is coming from someone who wanted one but couldn't afford it btw, and I still think the price is fair, my budget just wasn't high enough so I ordered a BTO 13" MBA with 8Gb of RAM.
Both the dirt cheap and ram are also soldered on.The price increase is not just for the Retina Display. They're also upgrading the hard drive from a dirt-cheap HDD to an expensive 256 GB SSD (about $230, depending on where you choose to shop). The RAM upgrade also adds on to that price. Not to mention the new ports+redesigned exterior of the new Pro.
I think $2199 is a perfect price.