Is it worth it to buy the deluxe?

IMHO, absolutely yes, for the centre stand (a necessity for any DIY maintenance), heated grips, self cancelling turn signals, and if you ever carry a passenger, they'll appreciate the backrest. You will also have the luggage brackets already installed if you get the Deluxe.

What are the differences between 2013 and 2014?

The only difference I'm aware of is that the '14 and later models have a different heat treatment on the 4th and 5th gears than does the '13.

Should I expect to pay more for a 2014?

It's a year newer than a '13. I would expect so.