There are guideline for posting in the B, S & T forum here
http://www.iceinspace.com.au/forum/showthread.php?t=46 that suggest including the price, but it is up to the individual.
Personally if you are trying to sell something I can't see why you'd not include the price. I know that if I visit a website that doesn't have prices for items listed and requires you to "contact" them for prices, I go elsewhere. Sure I
might miss out on a cheaper price (I haven't found that to be the case when I have contacted suppliers), but if I'm searching for something and I'm keen to buy I want to know the price now.
Otherwise I might change my mind and decide to hang onto my money
