I started replacing the old pressboard doors that look terrible and here's the first one. I have about 15 more to do. I'm using 2x lumber laminated about 3/4" thick. A single 2x8 8 Ft board will make 2 24x12" doors which comes out to about $2 per door plus my time and electric..
I just coated one to see how the bare wood would look, but the rest I'll make before coating with poly..