Garry, welcome to the site - non finer!!
My take on it is that their hope is that only serious buyers will bother to ask for the price. Sending pictures and price to a lot of dreamers and lookeeloo's is a waste of time for these guys.
When I want to sell a rifle or pistol, I place a picture and a price at the same time. By the time I have done so, I have decided on a firm price and that's what I want. But I know others have a different approach. I'm not much of a business man.