$300 to do just a frame?
The mirror blue is a basic powder $12/lb. Looks like you only need a single coat.

I had my frame  done on my old banshee. I paid $360 and this included them blasting, then stripping, then chemical prep of the metal, then 2 layers of color, then layer of clear. The powder was also $29/lb.
It would have only been $240 without the clearcoat. The clearcoat just adds more protection and makes it shinier.