I have had many questions on where I purchased my portable greenhouse. I got it at the garden center where I work. If you don't live in the Lancaster County area of Pennsylvania, that isn't gonna do you any good.
You can google Portable greenhouses and then click images (which I just did) and I see many of them at different places on the web. You may even try visiting your local garden center and see if they have any or can get one for you??
I only paid $39.99 for mine. It is well worth the investment as I can use it over and over again or even year round. I will take it outdoors in the spring and bring it back in over the winter to keep some of my tender plants until they can go back out the following spring.