Looks like similar construction to my first greenhouse. Basically plastic frame components with flimsy aluminum connectors. Mine was called "home hobby enthusiast" greenhouse or something like that.

Mine got me started and addicted, but I discovered in the first year it was not sturdy enough for the wind I get. Also, the glazing started separating from the frame due to summer heat and wind. Duct tape soon became a major component of my greenhouse. I discovered that a 40 mph wind severely distorted the shape and threatened destruction.

So, every time a strong wind was predicted, I drove a vehicle up beside it to try to protect it. Unfortunately, the weather predictors do not warn me about every strong wind, and I am not always around to try to protect my greenhouse. Anyway, a 70 mph unblocked wind totally destroyed it last September.

Because I am addicted, I shopped for a replacement and finally decided on one from BC Greenhouses that is supposed to withstand 95mph wind, for about 5 times the price I paid for the first one. My homeowners' insurance covered almost all the cost of the first one.

I got the new one too late to get it installed before last winter, and have been too busy to finish it this summer. Hope to complete it this September, in time to save my outdoor plants and have cool season vegetables this winter.
Looks very sturdy. Heavy aluminum "studs and rafters", 5 wall glazing.

Unless you live somewhere without wind, I would not buy a greenhouse with plastic framing.

I still have one of the Keter Costco ones described I think it was purchased around 2003 from Costco. It does not look like Keter makes these anymore. Mine has had panels blow off but I am able to reattached with various adhesives. It appears some similar brands are available on line under different manufacturers see the attached. http://www.greenhousemegastore.com/product/palram-hybrid-greenhouse/hobby-greenhouse-kits-by-brand