Selling paintings

It is very hard to come up with a price for a painting.  Do I use an hourly wage?  That sounds reasonable.  So I work on that premise then add on my cost for supplies and framing.  OK that's done,  I figured out the price.  Then I Realize it is more valuable than that to me.  The price is reasonable, but its a one off piece.  It will never happen again.  And after all its not everyone that can do this sort of thing.  So I go back and add a few more quid onto the price.  Mmm that's better!  But wait!  No one is going to spend that kind of money on a painting.  Who do I think I am?.  I am not famous after all.  Could I afford a painting at that price?  Then before you know what just happened you have knocked off more quid and now you are selling for less than you first price.  Oh forget the whole thing,  I really like this painting anyway.  I think I will keep it!