At this price, why don’t I just take the plunge and go for the full frame D750?
Absolutely! But this is where you need some crystal-clear thinking about where you want to go with your photography. If you’re looking for an all-round improvement in image quality, like exploring a mixture of subjects and are keen to progress as an artist or as a professional, the D750 is indeed the better choice. A DX-format camera like the D7500 is restricted partly by its sensor size, but also by lens choice; for the best choice of primes and constant-aperture zooms at both standard and shorter focal lengths, Nikon’s FX format is the way to go. But if your interest lies in sports/action/low-light photography, the D7500 delivers more bang for your buck.
The bottom line: If you can afford to buy the D7500, maybe you can afford to go full frame with the D750.