Commercial size?
Don't tease me... what size are you thinking of? I would love to set up two 10x12's like this one... 24x10
Two HFGH 10x12 Greenhouses Joined Together - Greenhouses & Garden Structures Forum - GardenWeb
These are the Harbor Freight Green House kits, they sell for 800 bucks, but if you are patient, you can get them on sale for 550-600. Then you need an additional 300+ to reinforce them. Plus laying the foundation. I hear you will end up at about a grand per unit. They are not put together that great out of the box, but they also don't cost 10k. And for my zone, and weather I don't need to worry about snow load, and wind above 50-60mph ever.