I decided on a pair of 20' over a single 40'. Currently trying to figure out best arrangement for roof...I have them spaced next to each other with about 15' between them. The idea is I needed quick secure storage to get out of renting a space, and I can use my truck and/or bobcat to drag these around to a more settled location eventually. I am actually liking the idea now of just building a standard new pole barn, and separating the containers each with it's own lean-to off it. One a tool shed and the other to park atvs. The main barn is nice to have not cluttered and not nearly as secure anyways if I leave the property.
Last summer I paid right at 6k for them both delivered, w/ tamper resistant welded on lock boxes. They are used but I'm fine with the dents and welds as overall they don't leak and seal up very tight, the rubber and latches are in OK shape. I picked them out from a yard that had hundreds for sale/rent of all kinds and these were the cheapest ones they had. E&J Trailer Cincinnati, OH, great place! I believe the guys name was David.