John, I think it can depend on the maker for any sails being sold on the second hand market.
If they are a set of racing sails,made with proper cloth they will appeal to a wider market than say,a set made from cheaper cloth from the budget end of the market.
Also you have the shape they were cut too,was it from a maker that has put some time into developing a shape and has prooved to be good on the race course.
Spinnakers are also subject to the above and also they are a sail that is surported less and handled much more so are open to more or less abuse!
Not sure what you paid or who made them but I would hang on to them at the moment,not a good time as you said as the end of the season. Also,what do you call a set,how many sails?
Try selling them via the class site, E Bay is for bargain hunters and not specific to Wayfarers alone.
C P 😀