I put up what amounts to a 25' x 14' tent with a steel frame. The price was a lot more than mentioned here (about $1100Can). These are shelters used in arctic conditions but are also supplied with covers that tolerate the sun in temperate areas. The estimated life of the cover is seven years in continuous service. The shelters are claimed to be snow, but not rain proof. In fact, they do pretty well in the rain.
The tent is supplied with 4' anchors, and the covers have wide aprons at the bottom. Recommended installation is to cover the aprons with around 6" of gravel. Mine has stood up is pretty good winds.
This type of product is very different from the 'picnic' sort of things sold in box stores. There are quite a few in use around here as permanent structures, and a neighbour has three of them. They basically are fairly inexpensive and durable for their size. Their advantage over pole structures is that they can be taken down and moved. another advantage is that they don't require a building permit, except for the very large sizes.
The only maintenance needed so far is that the snow does need to be cleared off the top sometimes. The structure will carry a fair load, but it's still not a framed roof. Snow removal is just pushing up on the roof from the inside. The cover is slick, and the snow just slides off.
Next year, I'll probably build my equipment shed. I said that last year, maybe it's because the shelter works well and I lost my motivation. Of course, with this year's implement purchases, I'm out of space and my motivation will probably return.
