I bought a small cheap ass chinese greenhouse. it didnt last a year, but while it was in operation, it was nice. i live in a colder climate in oz... i be had veg producing way before my neighbors.. me tomatoes came in 6 weeks before them..
the greenhouse failed because the joints connections were pvc slide ins.. the uv up here ate them up in less than a year..they became brittle... with the high winds we get and me anchors keeping da shit in place.. 80% of the joints eventually snapped apart. the next pre built greenhouse i get, if i get one, will be with screw/bolt joints.. the uv even ate at the film covering the structure.. so panels would be more cost effective imo.
i was hoping to get two years with the prebuilt unit.....well until i built my own larger permanent structue using polycarbonate panels, glass and reclaimed untreated wood.
i used sunken raised beds inside and surrounding it.. they went down about 18in and came up about 6-8in .... mostly cow manure and compost.. then had some shelving with potted plants.. heres the only photo i still have after putting it up.. the shelving wasnt in it.. but i used a step thang i created out of reclaimed metal mesh.. 4 levels..
the permanent is going to start where that greenhouse flap is open and run all the way back behind the old tin shed in the background behind itz... and it will be wider than the beds on the outside of the current ones i be made... i used the wire mesh and grew green beans on the side of da shed... some purple running beans.. good shit... .. the lady before me had used it to grow grapes.