Its funny you should mention LEDs going RGBA, because when I use
cyc lights, I try to use four cell ARBG to get more color combinations. R&G doesn't make a nice amber like an amber dedicated does. The orange from A&R is better then R&G and yellow from A&G I think looks better too.
I have also found that people have started putting more blue LEDs, less red and green because of the intensity difference. I doubt LEDs will free fall in price anytime soon, because there are plenty of people out there still willing to drop a grand for each light and not think about it. This not is an industry where stuff is cheap, thats for sure.