Conference or Stay Home?

I'm debating going to two different writers' conferences in the next few months.  I have friends at both conferences and certainly the chance to meet more.  I've looked over the presentation offerings for both and found a few workshops I might attend.  I like agent and editor panels and the glimpse they give me into their personalities.  Most of them come off as witty and interesting speakers.  I could always sit in another workshop on promotion.

What really attracts me to a writing conference though are the agents and editors attending and the chance to pitch to a desired editor or an agent.  I'm debating the cost of attending, one of them I wold have to stay overnight, and whether it's worth it to pay the money for a ten minute face to face. 

I can't decide.  What do you look for in selecting a conference?  How do you way the cost/benefit ratio? How many of you found your agent or publisher at a conference?