I have been to several of launches where Jim Harris from Gorilla Motors had some his demo motors. Several rockets were launched with green flame, red flame, white cloud and black cloud propellants. It launched the rockets so fast that I couldn't even get a photo of them. His red flame propellant is the best red propellant I have ever seen. Beautiful red with 7-8 mach diamonds. I downloaded the black cloud launch from one of the launch sites. I talked with him and he gave me these tentative prices (first $ is reload and the second $ is single-use):
Reload/Single-Use
54mm-4g K $70/90
54mm-5g K 85/120
54mm-7g K-L 125/170
75mm-3g L 145/200
75mm-5g M 260/320
152mm-3g O ---/1600
152mm-4g P ---/2200
There were more but these were the ones I remembered. Check out the photo.
Doc