DIY cedar chair for our deck. Here are the parts used.

One 2x4x8 cedar board:
https://www.lowes.com/pd/Top-Choice-2...
Three and a quarter of these cedar deck boards:
https://www.lowes.com/pd/Top-Choice-1...
About a quarter of the box of these screws:
https://www.amazon.com/gp/product/B01...
Six of these stainless bolts:
https://www.amazon.com/gp/product/B09...

If you build 4 chairs the numbers come out very nicely.