But again - if the laser cutter is an in-house machine that's kept busy then the cost per job is buttons.
I've used a piece of 3mm thick tube for the front crossmember and 2mm thick tubes for the diagonals (2 each side). Mainly because they were what I had on the steel pile - doing it again I'd use something lighter for the front crossmember. My frame will be heavier than a Mini frame but not by a lot and the engine and box are a good chunk lighter. To be honest I'm kicking myself a little for not weighing the frame beforehand so that I had a comparison. I do have a near standard Auto frame that I'll try to remember to do the comparison on before I throw them into the car.
Iain