Opinions are going to vary widely on this one.  NADA says from $36,000 to $43,000.  My gut feeling prior to looking it up was $40,000.  I don't have knowledge of your region, but my best guess is you are probably looking at a listing price of maybe $42k and will probably have to settle for closer to $38k unless there is a high demand in your area.  Be prepared to spend 6 months or more to find a buyer if you are looking for top dollar.  
I'm sorry to hear of your wife's battle.  Breast cancer seems to invade more and more of our lives all the time.  My wife is two year survivor.  My prayers go out to your wife, yourself and the rest of your family.  I also wish you the best of luck in your pursuit to sell the Raptor.