I get my lumber from a local mill, 7 minutes away. I actually have one of my beeyards across the street in a abandoned orchard.
I get my pine dressed (planed) to 7/8" x 9 3/4" at 50 cents a foot (deeps). I have to buy 7/8" x 8" dressed, and rip it down to 6 3/4" for the mediums, and I pay somewhere around 42 cents a foot for that. There may be a tiny bit of rough sawn on one side, but I just face that to the inside if there is. There are some big ugly knots here and there, but when I am marking them out I work those into my offcuts for the most part. Very little waste.
Titebond III and screws, cut hand holds, one coat of primer and 2 coats of paint, done. I have also been selling these assembled and primed, along with bottom boards, inner covers and telescoping covers. The last picture is the ones I made last year before I started using the molding head cutter for the nicer hand holds.