In the spirit of the season, as this item is a fundraiser for a family in need, I'll let the link stay. It's good to see the aquatic community band together for a family that has fallen on hard times.
That being said, I sure would bid against another TFF member, especially in a situation like this. I bid against other club members at local auctions, and you really have no choice at out monthly meeting auctions. One personal rule of mine is not bidding against younger kids, though once you are old enough to work you have a good enough idea of the value of a dollar, so you get treated like anyone else.
I do know of adults that will bid against kids, in those cases the kid usually drops out, and I will hop in just to drive the price up a little more, even if I don't want that item. I've only gotten stuck a couple of times, and end up giving the item to the kid. I have a real problem with adults that won't give a youngster a break.