Retirement luncheons

Just want to get a general opinion here. One of my co-workers is retiring and I'm being badgered to attend her going away luncheon. The cost of going is about $30. If it were the retirement of any of my close co-workers I would go. This lady has been something of a pain to me while I've worked here and I admit that I tend to go out of my way to avoid her. I have no close ties to her and to be honest, I just don't like her that much.

As such, am I being a jerk for not wanting to spend my time and money going to a luncheon for her? I'm trying to use the "somebody has to stay and be in the office" excuse, but I've been asked several times now and I simply don't want to go. Any thoughts?