Posting how much you donated doesn't help. For people in it solely for the prizes, if they see somebody post that they put in a bunch of money, it could make them think why bother, they won't have a good chance of winning anything, right? It's a shitty way of thinking, but back when I did fundraising, I was always told that.
On another note, is there any way this could be extended to get the total up? I mean I've been giving every time I get paid, and I'm gonna continue to do so after this is done I think, but would it help to add another week or two?