I would have moved the jar or at least made it clear where the money was going.

When you say you're not planning on selling anything beyond the included 4x6, don't cut yourself short. If the photos are good, show them, and if the owners want to buy more, sell them.

Pricing for rescue events is pretty much a matter of personal taste. I don't charge the group anything when I do a fundraiser event. I normally split the session fee 50/50 with them, and keep any print sales for myself.

I'm doing fewer and fewer mass events compared to what I did previously, but one I have coming up for a holiday fund-raiser goes like this:

$40 session fee which includes a choice of one 8x10 or one digital file as well as a coupon for a discount on an in-studio private session. The rescue gets half of the session fee, and half of the session fee for anyone who takes me up on the in-studio session as well.

My in-studio session is $350 and the discount is $150 so that leaves $100 for me and $100 for the rescue.

I've really gotten away from mass events because although I can run 20-30 folks through a mini-session, $600 for me and $600 for the rescue is hardly a big payday. Yes, every little bit counts, but I if I can do 10 in-studio sessions in a more relaxed environment, $1000 for each of us is a good bit better. Plus, print sales are much better from folks who will pay $200 for a session than they (normally) are from folks who will pay $40. Of course, there are exceptions, but not many.

I also do an in-studio mini session for $50 for a holiday set, no BG changes, etc.