Gravograph, Trotec and Epilog will sell you a high end solution to the quality of your Gravograph machines. You can however save an absolute fortune by buying from Custom Lasers , HPC Lasers or Boxford. If you have lots of work for the laser then go high end, if you are just starting and not sure how much work you have for the machines then go cheaper. You can get yourself a cheaper Co2 flatbed and Fiber and still have plenty of change compared to one high end machine.
Just make sure you buy from someone that can service and fix the machines if they go wrong (so not an ebay special)