Very easy and professional which is great. I know this isn't your fault, but I'm sick of seeing shades of blue colour for hosting templates! :p I think red or green would work on that template of yours!
As for what it's worth, I'm staying out of this one! Templates have dropped in price dramatically over the past few years, so it's pretty hard to say. It depends also what the buyer is also willing to pay, because after-all, he has a very wide varity of choice out there!
It's a fantastic template. I would charge $25 to $35 with rights but no coding. For installation and coding, you should cost extra. You should really look into starting something on the side, for a hobby, you sure are skilled :D
Looks nice. Very clean. Agree on prices above. I do graphic design as well, however, I often buy templates myself. Time is money, and when I have a customer that is on a budget, I find I can net more profit by buying a nice template, than spending 4-10 hours on various designs before I find what they want.