As a pro-photographer myself, I can say that these prices are reasonable. $69 for a 4x6 print may seem absurd to customers but there are other associated costs that goes into that print (paper, print lab, insurance, equipment costs etc). In fact the Professional Photographers of America studied that for a pro-photographer to break-even in the photography business - they should charge an 8x10 print $59 minimum ....
Your minimum of $59 for an 8x10 print compared to $89 by this photographer?
As a retired UK pro. my thoughts on charges were very much influenced by other trades. I remember an extremely costly plumber who, when I asked why he had charged soo much for just turning up, spending 15 minutes on site, solving the problem and leaving; at the time about a days wages for me. Responded with "They pay me for what I know, not how long I am on site".
In the same way I did not have an hourly rate; but fixed session fee for different scenarios e.g.. A single outdoor portrait to provide one image may have been £50 (twice the plumbers rate at the time) then prints would be charged (if the customer wanted me to supply them) at 33% mark up. Obviously there were no digital files in those days and selling negatives was definitely a no no!
I think I am saying a photographers skills are really his/hers product. The speed and accuracy of the service follow and to me the prints or finished product would be something that the photographer uses others to supply and therefor only adds their markup to mostly cover time spent/postage etc...
Obviously if the Photographer is providing all of this directly then composite charges can be made and savings possibly passed on.
To my mind if you are relying on the profit from one 6x4 print as a basis for a sustainable business you are in deep Ka Ka!
If my customers had all (strangely) decided only to have one 6x4 print off me then I would still have survived -JUST - but I would have survived.
Your name and reputation are your highest earners which is why they should be protected fiercely with your skills, your effort, your honesty absolute reliability Not forgetting brilliance of course
In this case the prize I would contribute would not mention print costs at all. It would be "A studio session with makeup artist and assistants PLUS a list of printed products, with an all encompassing value of £X" This would put me totally in control of costs (so that I know what I am giving away), give the impression of being a much bigger prize and not give rise to the kind of questions the OP has brought up.
The main question is this. Is the studio just trying to make a profit off a charitable contribution or not??
If the studio cannot afford to give this as a prize then they should not offer it - simple. No wonder there are so many short lived studio operators out there.
Regards
Sharkey