Hey Jim,
Excellent image choice! Glad to see you are giving too - awesome!
It's very satisfying when you can do it. Just handed off 2 images for the Botanical Gardens for their 2009 fundraiser and as you know I've contributed in the past to some very good causes (including memorial fundraising).
A suggestion: if possible, please encourage them to set a minimum bidding price that's reasonable if only one bid runs on it. This avoids the "yard sale" or fire sale" mentality. I've been there before and sometimes people aren't interested in fundraising for charity. They want a "deal", which is very unfortunate and not in the spirit of the fundraising. By having a minimum, you ensure a worthwhile return on your contribution to the cause. I've learned to stick to my principles on that one - it's worth it. YMMV...
Regards,
Marc