Forgive my ignorance ironmammoth - but isn't the expense in the CAD. Once that is done isn't it just a case of build to print. i.e. set it up, press print and then leave for the night and pick up a fully printed Stalinggrad factory then next morning?
I do the CAD myself. As Oliver said, there are cost to running the laser cutter. The actual laser cartridge in the laser cutter has a finite life and when that needs to be refilled/replaced it costs £1000, that has to be factored into the cost. Also the filters in the extractor have to be replaced a couple of times a year and they cost around £400 a set. Then there is the support honeycomb, which deteriorates with use and needs to be replaced at least annually. There is also the service contract on the machine which is £300 a year.
There is also the initial outlay for the machine, which need to be factored into the cost - £18000.
Admitted the 2mm MDF is very cheap! However MDF is a dirty material to lasercut and it accelerates the wear and tear on the machine...