Cheapest place for 3rd gen rear seat storage

Where is the cheapest place to buy the rear seat storage ?

 

I have looked for years and never found a price worth pulling the trigger. Local sale from someone selling truck would be ideal, but what are the chances. I had a lucky find 2 weeks ago getting a swing case for $150 but never find good stuff locally.
I will eventually go buy 2 or 3 plastic "hotel pans" and make my own with some plywood and bedliner or spray paint. I wanna be sub $50ish, unless I could find an ESP for $100ish

 

https://www.tundras.com/threads/for-sale-used-esp-truck-floor-storage-crewmax.53865/#post-1407936

 

I use this behind the seat, attached it to the vinyl back cab wall:

https://www.ebay.com/ulk/itm/183935157891