If it's just for a college course, you could just get a "working version" of VB. They often come packaged with a book and are basically the same as a regular version, except they won't build an executable.
Or, if you think you'll use it again, you may want to avail yourself of the educational discount at the campus book store. I think the Standard and Professional Editions VB 6 compiler goes for about $50 and $100 after educational discount. Still not cheap, but it's about 80% off.