There's a few ways to decide price, and asking random people is not one of them.
This is probably true - the people you need to ask are the people who would be your target market, and to be truthful, they are probably not going to be the types to spend $25 on something they can't smoke
I know how difficult it can be when you put a lot of time into something. I have had people ask me to make certain items for them and I have out and out told them that they probably wouldn't be willing to pay the price for so many hours of my time. It's certainly not a lost cause, but maybe you just need to branch out to some other audiences. (The idea of having a head shop sell them on commision isn't a bad one either - impulse buy!