What is the "Higher quality legend process"? Is it something different from normal dye sublimation?
Absolutely. Because of the smallish legends on this set and the importance of the font to the overall theme, we opted to use a rare high-end screen-printed dye-sublimation process (not used on Granite or, to my knowledge, any other recent GeekHack group buy). It yields much crisper legends.
Here is a photo comparing the two processes. The two outer keys are examples of LCARS legends printed using the normal process. The keys on the inside are keys printed for another job (a phone keypad) using the screenprint process. The difference should be obvious in the picture, but I can vouch that in person the difference is even more noticeable.
So, yes, there is a premium price. But this is a small-run hobbyist project using the highest-end processes available (we're also doing other things like a custom-mixed Pantone-matched resin color), so that's somewhat to be expected. And I take SP at their word about the extra challenges and cost of the Tsangan set in its current configuration. I'm not sure what else to say beyond that. Given that we're doing things that haven't really been done before, I don't think there is a baseline for comparison to decide what is or isn't a fair price. Each person can decide privately whether it's worth it to him or her.