If you're doing it yourself, drywall is very inexpensive. You could even save the taping, mudding, sanding, and painting steps for a future time.

I'm in the process of estimating the cost of finishing my basement and am looking at using a dropped fiberglass tile ceiling. The prep and installation work required for a dropped ceiling isn't as demanding as drywall, and it allows easy access to my overhead wiring, gas and plumbing should I need to get to anything.

I've gone to the Armstrong site and downloaded their material estimator program, which gave me an estimated list of materials, which I then went to my local orange warehouse and priced it out.