Is the k model one with an unlocked cpu multiplier or something. I can't figure out the differences between them to justify the higher price of the k model.
To answer your question, Yes, the 3770k has an unlocked multiplier and it is for that very reason that the "k" version is so much more.
with the stock 3770, the speed of the CPU is pretty much set and can't be changed (technically, there are ways to increase the speed but it's pretty cumbersome and you won't be able to speed up the CPU too much). The 3770k, on the other hand, has the unlocked multiplier which allows people to increase the CPU speed (overclock) much more easily and to achieve much higher speeds. Intel is essentially charging you for the ability to increase the CPU speed. For enthusiasts, the money is considered well spent.
Hope this helps.