LFR is just like any other D&D game, just generally with more random players. You can have a lot of fun without dropping loads of cash because the fun is what it's all about.
Yes, I like the "who's on deck" approach. Most LFR DMs I've played with do that, and it helps the game go much more smoothly.
To be clear, I'm not planning on dropping loads of cash; one time only, I'm planning to print out some color maps on my regular home printer. Plus, the particular maps I'm printing might be generic enough that I could use them again in a home game someday. So, no great expense, I promise!
In case anyone is interested, I ran the LFR adventure in question today and had a blast. More importantly, the players did, too! Thanks again for the advice, all of which was put to good use.
The full write-up of the session and my preparation for it can be found on my blog.