I've been on the road for the 1st 2 closings and will likely miss tonight as well. But I'll sure try hard the last two nights!
I generally will run items up as far as I am comfortable early in the bidding. But I sometimes will save a shot for a final salvo in case someone else jumps in at the end. And I've also been known to bump my own bid in the final minutes to try to keep the snipers on their toes.
It's all in good fun with the ultimate goal being to help the kids. If I end up with a cool item on some, that is just a bonus. Bid early, bid high, and fire a final shot aggression the end!