I have one out back that I have had since the early eighty's. I paid $275 for it. It has steel endcaps, but that is all that is steel. The rest is aluminum, and it weighs 3500 pounds and is forty feet long. I sat my on an incline to where one end was sitting on the ground, and the floor rotted out on that end. A little air flow is a good thing to have under it. Set it off the ground on something extra sturdy and build a ramp up to the door if you plan on the floor lasting any time at all. (You guys in the desert can ignore that part).
I don't use it much anymore, and have considered scrapping it out, just hate to send it to the scrapyard. It is worth more in scrap than it is worth as a container. I have moved it three times and it can be fun to move, lol!
I wouldn't hesitate to buy another if I needed a quick building and looks weren't a problem. There are different styles of them, some have different door heights, insulation, roll-up doors, refrideration units (diesel heat pumps) and the list goes on, especially if you get into dedicated freight containers that are built to handle a certain type of freight. I have a friend that purchased 4 of them that were 12 feet wide and 9'6" door openings, 53 feet long. He got them for about $600 each because they required a wide load permit to move them. He just got a wrecker company to move them, about 40 miles for $200 each. He stacked them two high and built a roof over them, and has a really nice shop in between, with stairs built up to the second level for storage.
David from jax