[Tilted Irish Kilt]

trisham:" I hear you, but my interest in a greenhouse is to allow for a 12 month option of growing plants and starting seeds."

For the record, I have worked in a commercial greenhouse (4 acres under glass/plastic), florist , doing cuttings, transplants, and retail and commercial sales.
If you are committed to a twelve month growing season ,
you are already married to it (grain farmer /dairy farmer), and have your priorities set.
Then take Cynicalbear's suggestion and look for one avialable for sale either on Craigslist, or some other reseller in your area.

[trisham]

I looked on Craigslist. :)