I don't mind dirty and in a jumble so much but I do like to see prices. I HATE standing there trying to get the seller's attention while he's blabbing to his buddies and paying no attention to buyers or worse yet asking his buddy or spouse and getting "I don't know, he's not here right now but will be back later". If it's not priced, I move on unless it's something I think I just have to have.
When I set up, everything has a price on it. I also display a sign that says "reasonable offers accepted, crazy offers considered". If someone is looking over my items and looks to be trying to make eye contact, I jump up from my chair and see if I can help them. I don't rush out to try and make a hard sell because people hate that too, but I realize people are trying to cover a lot of ground and I don't want to keep them waiting if they have a question.