SMT Do you feel there might be a market for a 2" metal embossed ball marker that can be made emblazoned with your choice of design on both sides?
I may be the only one who thinks this way, but I don't see the point in spending money on a ball marker when a small coin does the job perfectly well (and better than the poker chip-type markers that I see some others using). To my mind, a 2" diameter disc isn't really fit for purpose - it's far bigger than you need to mark a golf ball.
(Just my opinion, though, and I'm sure that there are many out there who will disagree.)