Why the big price difference between flatbed and slide-in??

[Skinhyfish]

in 2022 we experimented with a similar design like this . Turns out the additional weight and complexity during assembly made it unattractive for us to take it any further.
View attachment 827810

What tray is that?

 

[FreedomTraveler]

Any idea where I could sell a like new 8' 2nd Gen Tundra bed?

I sold my Chevy bed on Craigslist and my Ford bed on FB Marketplace. Just research what the junk yards are selling them for and be a bit cheeper. Given that the Tundra is lower production should make it easy to sell.