Some belts are only given out to people with skill. Those belts are quite often worth something to the people who receive them. A belt from a quality instructor is different to a belt that is bought on eBay.
But as has been pointed out ad nauseam, the belt itself has no value (OK, it's worth a few bucks for the material and workmanship...). It's the skills that matter. I'd rather have compliments from my seniors and/or see the progression of those I train than another belt (or stripe, or whatever).
What I gain from my training, and what I try to give students, is completely separate from any belt.