Reddit mentions of New Digital Shore Durometer Rubber Hardness Tester Meter LCD Display Type D

Judging by how the Shore scales overlap, you probably want to be using D anyway: http://www.imperialrubber.com/images/03-numerical-comparison-of-shore-scales-for-measuring-hardness.jpg You can always convert into another scale if you really want.

Here is the same meter that you found for less money and ships from Amazon: https://www.amazon.com/Digital-Durometer-Rubber-Hardness-Display/dp/B01ET0E2UA/

I would just buy that and try it out. The reviews you posted seemed mostly positive aside from one asshole who left one star because he's an idiot, one guy that got a defective unit, and another guy who said it isn't accurate (no idea what he was actually doing with it).

Buy it from Amazon and return it if it isn't working.

You aren't going to get exceedingly accurate readings with a device that isn't a piece of actual lab equipment. This is serious business. We're talking very precise tip geometries, forces/springs and measuring equipment (think micrometer or dial indicator). https://en.wikipedia.org/wiki/Shore_durometer

I would buy the cheap meter and then a calibration set: https://www.amazon.com/Mitutoyo-64AAA590-Calibration-Included-Mahogany/dp/B007FFTUGI

You can determine a correlation between your readings and known values. Plot the three points in excel to generate a best fit line and equation, plug the values from the cheap meter in and bingo. You will still be under $250 and you can buy a the right used shore tester when it pops up on ebay.