I built mine from salvaged/scrounged lumber, I think the only thing I bought was the stain and urethane varnish to color and seal the work surface.
Here are some shots of it (I apologize for a duplicate post):
That was taken over Christmas vacation, but it still looks pretty much the same. Before I bought my house, I was living in a mobile home, saving money for a house. This bench was carmmed into a spare room that was about 10'x10', and that determined the dimensions, it's about 4'x8'.
As you can see, it's oil-fired, to power the Dremel. Note the tank behind and the burner to the right...No, just kidding! It's in the utility side of my basement.
2x4's for the framing came from a theater I belong to, when we struck a set, and the work surface is made up of 4 pieces of 3/4" plywood shelves that I got at work (they were being thrown out).
I've since added two more legs about 2' in from the left end of the table, front and back side, and a rail on each, to support some pine board shelving. That holds more of my kit stash. The rest of the stash is behind the camera's position.
I'm thinking of adding some shelves along the back of the bench, to add more storage for things that I need to access, but are currently on the bench itself and in the way.
It's true, isn't it--you always need a bigger bench...