If you view the users classifieds profile that is where feedback can be entered.
Asking price is perfectly normal for a regular ad. Buy it now is a function to allow a user to purchase the ad online through paypal. Users can elect whether or not to allow buy it now.
The asking price is the price the user wants for there ad. In an auction that would be used as a starting point for bidding where as the normal ad you put the price you want.
The buy it now on an auction the user puts the price they would sell the item for to end an auction. On a normal ad the user would put the price they want so asking price and buy it now would be the same on a normal ad.
As stated above the user can elect not to allow buy it now.