Ignore the surrounding mess, but this is the setup I will eventually have for mine:




Purchased on Craigslist last summer from a print shop that was closing. The owner's daughter was selling the flat files for $25 each and the stands for free, until demand was so great she raised the price to $50 for a file and $15 for a stand. I had a stand and file lined up for $25, but miscalculated how big it was so couldn't fit the stand in my minivan. Went back after removing the seats to get another file, this time for $50, and a stand for $15. All told, $90, and some elboqw grease to get some ink off the cabinets. Still haven't actually put in posters in there, but I will and hopefully soon.
Patience is key, but yeah CL will be your best bet.