BTW please check your books when you say
"As a non-profit organisation, we of course canít compete with commercial outfits that may pay top dollar".
with staff cost in the $900K region and lease at $140K and a big bank account, you're very much richer than a lot of commercial outfits.
Don't get me wrong, like many here, I've shot for free before and will still do so, in fact we had use our own money and time to run projects for charity. What we take issues with are people who can affort to pay but come here under the guise of NPO, Charity or no budget and asking for free or low budget photography.