That means that asking someone to suggest how much he would charge for his product or work means you may have better chance of get a deal, as you see it, than suggesting the price.
It began as a relatively simple tale of two characters, meeting by chance very early on a fine May morning (meaning, one assumes, it wasn't actually raining) while walking out of London up Tottenham hill, and spending their time in the discussion and practice of the joys of fishing.