Here is my 2 ft by 4 ft workbench that I just recently finished. It’s made entirely of pine and douglas fur boards that I picked up from Home Depot, I think the total cost was maybe $20. The outside apron is the only part that is held together with screws, everything else is mortise and tenon. This was the first time I’ve attempted mortise and tenon joinery and I think they turned out great. The mortises for the stretcher on the bottom was cut with a laminate trim router because it was all I had at the moment, I think I made 10 passes because I would only take an 1/8” at the most. The botton part of the legs were made of 3 2×4’s glued together. There is also a 2” deep rabbit in the 2×6 apron, in which a 2” thick torsion box sits. The top is made from hardboard.