when i played in bands in college, we used money from jobs we had, gigs we played, and change from the couch. if you’re doing just a 3 or 4 song demo, then it’s not too expensive. there’s no point in spending all your money on a full length cd if you can’t afford to do so. plus, you almost have to sign with a label at some point to take care of the cost, unless you have a huge following and are making a ton at shows. or mom and dad are willing to pay the bills.