I think you'll know if it's your thing within a day of riding it. I have let several people try my XR and none of them ate shit right out of the gate. It's a lot to spend for something that may just not get used, but it's worth every penny it of you get the "stoke".
I'm 46 and was a snowboarder 20 years ago. The feeling of being able to carve like you're in deep power while going up hill is pretty euphoric. Riding across trolley tracks in the city or sidewalks that are broken up by tree roots is also no sweat when you're commuting. It's an amazing machine and the injury risk is pretty manageable, both with protective gear and your mindset.
On the practical side though, it uses muscles you haven't even read about. Having to constantly keep your weight on your front foot to move forward is incredibly fatiguing at first. Plus there are no bindings to support your ankles so all of your "heel side to toe side" inputs require a lot of effort with your calves and arches. The point being you will not jump on this thing and go for miles and mile the first few weeks. The depreciation drops off pretty quickly after a year. I recommend getting a used Plus or Pint. You wont use the range of the XR for a while. When you find yourself wanting longer days on the board you can sell what you have for probably close to what you paid for it and then put that towards the XR.
By the way, I'm biased in that the XR is really the only Onewheel in my opinion. everything else is a stepping stone to the XR :P