Hi Denise, limited numbers and higher prices work very well for established photographers and may be a way to recoup the expense of your firends investment.
I went to an exhibition of photos by Nick Brandt yesterday
http://www.nickbrandt.com/ for ten years he has been going to Africa and has 94 shots to his credit.
The eighth and last copy of this print
http://www.nickbrandt.com/portfolio....&nS=0&i=176193 just sold for $150 000, so limited quantities and high prices are working well for him.