This is very true. Instead of selling your business off completely, why not go into a partnership with your friend. A good friend should be able to assist you in your business especially in your difficult moments.To be sincere I think that there is no point to sell a business to a freind to be sincere that is not good at all why not keep that business its can be as a source of income for you in the nearest future.so I dont see any need for you to sell your business at all.