Belts don't matter to me, but if I'm going to deign to "earn" a black belt, it should be worth more than the cost of materials it cost to make it.
There are Benefits to Rank besides Prestige, and whatnot.
It really depends on how the Organisation Works.
For Example; Where I Train, Black Belts Spar Full Contact without Gear, based on the Idealogy that by that Point, they should be Skilled enough in all Aspects to manage it - And most of the Time, avoid being hit overall.
Belts can be a Mark of Recognition, more than an Object of Prestige.
As well as a way for Instructors to know someones General Skill Level.
In Short, I dont consider Belts to be some kind of Reward.
Ive never had to pay for one, ill never pay for one, and ill never request one.
But my Belt essentially Coincides with my Understanding of the Art, the Contents of the Art, and my Skill within the Art.
Otherwise, youd have Beginners being killed by Advanced Students, and that is possibly a literal statement.
Say you did Proper Kickboxing.
Since Belts are Irrelevant to you, would you mind Sparring a Black Belt, on condition he doesnt wear his Belt, doesnt tell you his Belt, and doesnt hold back?
You wouldnt know any different until it was too late. Not that you could do anything anyway.
-This is mostly Retrospect on Belts, Ranks, and other Symbols. Since its Easy for Beginners, or Students at Laid Back Places to not consider what Belts should Represent, besides some kind of Hallmark.