For me, they are worth everything. I live for ideas. Without ideas, I think I would die of boredom.
Fortunately they flow around me like drops of water in a stream. The biggest fountain of ideas is questions. There are a lot of questions around—fluther is one of the question wholesalers, but there are other places.
In any case, while there is a marketplace of ideas, and I suppose that is one measure of the value of an idea, I think it is the individual who establishes the value of an idea, albeit, only for themselves. But then, what else matters, when considering ideas? Hmmm?