You might find on craigslist but sometimes not very reasonable. You know they are out there, unused now but maybe people just forgot they are in the garage. Maybe yard sales, thrift stores...just have to keep looking. Not easy to find; I just got very lucky this time.
I bought one last week, used once (still had one new cover too) with the stand which is about $50 by itself, new (not worth that new price IMHO), both for $20 total. I didn't quibble about the price after I saw the pristine condition. But you can't beat free, even if old