It all depends on pricing and condition in this market. Every area is different but I know where we are, if you create value to a potential buyer these properties seem to move very quickly. Key is being aware of your market conditions and pricing accordingly based on that. Good luck with your sale and hopefully its already sold!
I think your best bet is just being honest with them. If they are a true friend they will understand how you feel. In this business we always hear cases where someone has used a friend to help them and they have felt they weren't getting the best service. Its nothing against your friend, but this is one of the biggest decisions you make and you need someone working for you. It will all workout! Good luck with breaking the news and selling/ finding your perfect home :)