I get your point, but your not going to change others. Hell, the amount of people that will actually read this is very low.
You have to adapt to the way things are, and if you cant take 3 seconds to hit CTRL+F ->(sold or banana)->ENTER then I dont know how else to help you.
The first thing I do when looking for an item in the classifides is to scroll down to find a price and see if its sold. Its not hard to gain the habbit and I'm sure its what a lot of people do.
Then report such posts.
Report any post againt the rules, its the ony way it will stop. People are ignorant and do not read the rules and they will suffer for it! =D