The main point here is that I want to play, but game prices limit my purchases.
I'm going to sound like a jerk saying this, but if you can't pay, don't play.
I don't know if you realized this, but Fantasy Flight Games (who makes the LCGs) actually owns this site, so you are basically going to a company's forum and asking for ways to play their games without making any purchases. Seems a little underhanded to me.
But don't get too discouraged about the money. Nobody ever said you need a full play set to play these games. Just buy a core set to start off with. It's only $40 ($27 online) and is a lot of fun. Then you can just pick up the expansions that suit your fancy as you want them. It doesn't have to be a life-consuming investment.