I worked out of one for a long time, and it was great for a temporary structure. Every few years, I fix up the top (it is a peaked roof style with pointy peaks), and now we use it as a shade house. I purchased it as an old greenhouse, and changed from the plastic about 4-5 years ago. The peak style allows for snow to slide right off. 25x50 is the size here with a 16' or so peak. I can drive my 2.5 yard load into it with ease. No idea on the price, this one is really heavy duty, but I bought the frame used and my friend duplicated the pipes as needed to expand or repair it.
A couple years ago we put a round top house on top of our mafia block bins. This style works well too, and is smoother, with the heavier vinyl top. Putting one up on blocks helps with clearance, and if you use it for storage, will also help with security if you put it 6-8' high. This one is way up high (triaxles can dump inside of it), and is also about 25x50. This one is a duplicate of our cold frame winter greenhouse with the round hoops.
You can see both if you hook up with Guido's equipment page. It is under my section, called Phil's...
http://content.communities.msn.com/GuidosEquipmentPics/PhotoAlbum
My friend Ron owns Quickshelter, in West Haven, about a mile from our shop, and he ships all over the world. He fabricates them to your specs. (203) 937-8990 (I think).