I have been calibrating my monitor using an i1 Display pro.... [M]y major problem wasn't color inaccuracy but prints coming out too dark rather. Long story short, I have decided to get a spectrophotometer.... I appreciate your feedback.
Insofar as your major problem is prints coming out too dark, why don't you simply try setting a lower target when you calibrate and profile your monitor with your i1 Display Pro? E.g., if you're telling the software you want 120 cd/m^2, why don't you try 100 cd/m^2 or even 80 cd/m^2 and see whether that largely solves your major problem?
In a related vein, why are you considering getting a spectrophotometer? How is that going to address your major problem? The best printer profile in the world isn't going to compensate for your monitor being too bright.
All of that said, FWIW:
* the i1Studio is a wholly different device with wholly different X-Rite software. I've rented it, and now I have its predecessor, the ColorMunki Photo. It's fine for my purposes. Of course YMMV. So I suggest maybe you rent one (e.g.,
https://www.lensrentals.com/rent/x-rite-i1studio-spectrophotometer), and see whether you think it puts you on a helpful course.
* If you feel like the rented i1Studio puts you on a helpful course but you decide you want something more sophisticated, powerful, and flexible, then you can consider the the various i1 Pro 2 and i1 Pro 3 models and their various differences, pros, and cons.
* I seem to recall that maybe the difference between an i1 Pro 2 and i1 Photo Pro 2 may be what X-Rite software / software capabilities they do and don't have. X-Rite sometimes locks out certain software capabilities for otherwise-very-similar hardware, I guess as market segmentation.
* Whether you can a used ColorMunki Photo or the latest new i1 Photo Pro 3, more than a few will think you can do more / better using Argyll CMS instead of the X-Rite software. For an expert that may very well be true. For me, I'm pretty happy with the basic i1Studio software. How deep a dive do you want to take?
* For that matter, how deep a dive does your wallet want to take?