That said, the difference in your mini system won't be audible or may be subtle at best. Don't overspend if you are going to keep your mini system.
Meaning that since you have a budget sound system, it would not make sense to buy an expensive high-end TT and cart. You would not be able to fully appreciate the high quality sound and the benefits that come with it...such as more detail, better dynamics, less surface noise on the LP.
If you were to upgrade from the Denon mini to a more revealing system, then you could easily hear the difference in sound quality between TTs and carts.
So if you are planning to upgrade from the mini in the future, then you should buy the best TT you can afford.