I think it is perfectly fine to let someone know about prices.. as long as it is done in a tactful manner. Sometimes it is just the way people "say" things on the boards. It is hard to be able to know how to take things without the voice inflections and pauses. I say just think about the way to say it, then you should send a PM. If the cacher is a "real" cacher then they will act accordingly. If they don't you can take it from there. They at least need one chance to make it right before you "out" them. Sometimes noobs don't know, and here on the forums they can do their research with real people who have a little more experience. We sure don't want to scare off any future cachers by stating something that could easily be misconstrued. do we?????
"To the world you may be one person, but to one person you may be the world."