Greenhouse by Exaco. There's no prices on the website.
Greenhouse by Duramax at Lowe's. This one is under $1000 and is the largest so far for our budget. 70 square feet. I'd like to be able to attach shelves along the sides. I don't know if this is possible. If not I'd have to buy metal shelving units to maximize space.
The biggest consideration for choosing a greenhouse here is wind. It would be pure foolishness to consider anything with soft walls such as polyethylene. I might as well throw my money out the window.
I have awhile to consider what I will get. It's pretty much too warm here now to have anything growing in a greenhouse. It would only be used for storage or protecting plants at night from critters.
My only other choice is to carve out space somewhere in my house for 3 months out of the year and just be more patient with growing inside.