Cattle Panels: $25 apiece, used 2
Greenhouse Plastic: $30 remnant left over from replacing plastic on the big greenhouse last Fall.
Pallets: Reclaimed, free. If I buy them it is $5 apiece and I used 4.
Lumber: Reclaimed from 80-year-old farm buildings in 2017. Mostly a rotting chicken coop. If not free reclaimed I would have used pallets on the sides too. So it would have been 12 pallets for long and short sides of beds.
Extra Plastic For Ends: From mattress store, ruined but worked doubled over.
Plastic for Door: $3 worth of plastic from a $20 roll of painter's plastic.
Corner Reinforced Hose: Reclaimed from my dad's farm 15 years ago. I have also used bailing twine and it works just as well.
Screws: Reclaimed from last hotbed, free. Probably about $3 worth if I went to store for them.
Corner Elbows: $1.75 apiece. I used 8 for $16.
PVC For Secondary Door Plastic Arch: $3.