Used greenhouse, unless you're very lucky you may get old looking for
something local. I've been looking for a few years now. I have found a few
but they have never been local and required disassembly which isn't too bad
till you go to Uhaul. In most cases you could buy a greenhouse new cheaper
than renting a Uhaul truck to cart a used one across country. I've found a
couple local (the lean-to kind you find on restaurants) however the scrap
value is worth more than their time to wait for someone to take it down.
ARRGGHH! Give me an upset stomach just thinking about that.
If you have a Harbor Freight store near you they had and ad for the
following green house priced at $299. To see it just put the item number in
the search box. The on line price is higher than the local store prices. Oh
yeah someone on Ebay was selling this for $500 using the same picture.

http://www.harborfreight.com/
47712-4VGA
8 FT. x 6 FT. GREENHOUSE

This url has used greenhouses listed but they are usually very big.
http://www.h2othouse.com/index1.html

I whish you a whole lot of luck in your quest.
Grow well and bloom magnificently
Dusty