Cartridge Change

I have a Rega RP 3 Turntable with a Rega Exact 2 cartridge with around 300 hours on it. Was wondering if a Ortofon Bronze would be a step up or would I have to go the the Black to make a big difference. I could buy the Bronze today would be a couple of months before I could get the Black. I’m happy with the Exact just the table came with a Rega cartridge and when I upgraded I went with the Exact so I’ve never heard another cartridge. Want to stay with a MM cartridge when I do upgrade. Thanks for any input.
Try some classics, you will quickly realize what the true MM sound with classic high-end MM cartridge, not that modern MM.

The budget is ... ??
Not the kind of thing I would ever do. My approach has always been to never bother buying anything I don't think will make me happy for a good long time. Years. Because years of use takes the sting of depreciation loss right out of the picture. Cartridges especially are a total loser to be swapping like this. For what it will cost in price differential you could probably buy some footers or a shelf that will cost the same but you lost zero on the deal and the footers and shelf are good for live.  

The cart you have is gonna go to near zero soon enough anyway. Why the big rush?
Nagaoka and Dynavector are both said to play well on a Rega table - I'd look at whatever fits in your budget from those brands.

Dynavector is all MC but they do make high output that should work for you.

Rega carts are just OK I am running an Apheta 2 on an RP10 and even at that level it's quite good but not incredible, I've heard the Planar 3 with whatever MM it comes with from factory and it can be significantly bettered - even a Nagaoka MP110 has a lot more warmth and soul going for it.
Those Nagaoka with aluminum cantilever and bonded elliptical styli are not good. In your situation It’s like changing one to another without any serious upgrade in sound quality.

Cartridge is the most important part If you want to extract music from those black vinyl discs.

Your next cartridge can be significantly better, and even if it cost more it’s better to pay a bit more to get what you want (a better sound).

Look for the cartridges with advanced stylus profile (line contact type), make sure it’s "nude" stylus (not bonded). Lighter moving mass (stylus/cantilever) will give you a wider frequency response. The advanced stylus profile will give you less record wear and better quality. LineContact profile will serve you much longer than conical or elliptical.

In the past an MM cartridge could have a very nice cantilevers like Beryllium, Boron, Titanium ... and nude diamonds like MicroRidge. Today it is a rare option only for very expensive MM models.

This is basic recommendations.