Sometimes, you can never say it enough ... xD
I would also add that if you're requesting for crafting help, one should come prepared with all the materials unless otherwise agreed on. A little respect & patience on the side would be nice. We don't tend to mind questions, but for things like Enchanting, materials required for entrusting are stated on the wiki and not hard to figure out where they come from, so check that first if you can.
As for price checks, I'd use housing as a baseline, but since it's generally rather overpriced, I wouldn't solely base it off that. Skimming party chat or checking out personal shops and kiosks can generally give you a good idea of the value of an item, especially if it's well circulated during that time. It doesn't really bother me when people ask about them though, since some items are incredibly vague, esp. if you don't see them around as often as you'd like to.
Another thing I'd say that gets to me a bit is asking someone to repeat themselves / asking what's going on without even trying to read the log first. I mean, I understand if you just cc'd in, but if you haven't, I don't really know what's stopping someone from reading the log. It saves the other person the trouble of typing it all out again, and saves you- I'll stop there.