I have four (found on craigslist). Mine do not have the hinged door, but otherwise are the same. I purchased mine for $25 each. I really like them. They are versatile have many uses. I love the fact that they assemble with just the brackets.
I'm still experimenting on how to use them. We added inexpensive screen doors reinforced with heavy wire screen to keep predators out. Originally we tried putting Ondura panels on the top for a roof. With the panels and the framing to make them slope the roof was HEAVY. The floors are also very HEAVY, they are basically well made solid pallets. I emphasize the big and HEAVY because I usually have to move the panels and put the things together by myself. This would be a snap with an extra set of hands.
When I picked mine up they were all taken apart. Make sure you get matching panels. We had to pick through several piles to get walls, floors and roofs that matched. Some of the units are slightly (1 or 2 inches) smaller than others.
Also remember they were made to be stored inside and are probably made of untreated wood, unlike a shed kit you may buy.