Do you really have a problem paying just $350 for a highly specialised piece of equipment? If you're a student and want to grade at home it's a third of the price of the next cheapest piece of kit! And if you're working professionally a day's work or less could pay for this thing.
The quality of the manufacturing is probably (but not definitely, for sure) higher, and economies of scale mean that fewer of these are produced so the cost-per-item is greater for the manufacturer.
Oh course, even after that you are paying a certain amount of professional premium. But charge it to your clients! If you can't make money off it or it's not work the investment as a student, don't buy it.