Finishing the Basement?

Today I had a contractor come over to talk about finishing our basement!! We built our house 8 years ago and have had an unfinished basement. Buddy is starting high school next year and since we live really close to the high school, I have a feeling a bunch of his friends might be hanging out at our house. I really don't want them in my family room and kitchen!

If money were no object (ha ha) we'd put a small kitchen down there, built ins and a bathroom with shower. What I'm hoping is that we can at least afford to finish the walls and ceiling and put carpet in, but the other stuff sure would be nice!!