If you do purchase a laser engraver, you will more than likely never pay off the investment. Engravers can cost from $10,000 to $25,000+ based on the model. If you are looking to invest in one for profit, you will have to do other jobs other than turkey calls. Say that you make 5 calls per week (which is rather high production for a an average do it for fun call maker) and you charge 10 extra dollars for lasering the call which would equal to about $2500 per year. That's 4-10+ years without any turnaround. This does not factor in the cost of running the machine (electric bill), or repairs. By the time you would pay it off, you'll likely be due for a new machine. Unless you are purchasing a laser and looking for a profit and lasering objects other than just calls, I would recommend sticking with your guy to do lasering. Ask him how much his machine costs, what it costs to operate, and how long it took for him to make a profit.
