The K4 Pro would certainly be a good and inexpensive intro.I don't have enough addictions so I'm thinking about crossing over to the mechanical keyboard world. Currently using an MX Keys which I like a heck of a lot better than the Apple Magic Keyboard which I also have on my desk so I can use the TouchID.
Requirements for me are backlit, numeric keypad and wireless. Considering the Keychron K4 Pro, RGB backlight, brown switches. (On AMZN for $99 and one day shipping) Is this a good entry point in to mechanical keyboards? Without the ability to test a bunch of them I'm kind of guessing.
Any recommendations and advice would be welcomed.
One thing to be aware of -- the keycaps on the K4 Pro are not shine-through. While there is backlighting on the keyboard, the light will not shine through the keycaps.
If you want/need keycaps that are backlit, consider the K4 v2 (not the Pro):

Keychron K4 Wireless Mechanical Keyboard (Version 2)
Keychron K4 (Version 2) Wireless Mechanical Keyboard. 96% Layout but Compact. Wireless or Wired. Bluetooth 5.1. For Mac and Windows. Optical or Gateron Switches. Connect up to 3 devices. Inclined bottom frame. 15+ RGB Backlight. Dedicated caps lock indicator light.

Or there are other similar models if you don't need the numeric keypad (plus a full-sized K10 if you prefer a full layout to the 96% layout of the K4).
If you go with one of the "regular" K-series, do note the aluminum case option for some models -- they have a more solid feel, but it will likely reduce your Bluetooth range. If you need best possible BT connection, then go with the normal plastic case. I have an aluminum-cased RGB backlit K4 v2 with tactile brown switches in my office at work -- it's a great intro mechanical keyboard with backlit keys and shine-through keycaps, but I use it in wired mode, so I can't comment on the strength of the Bluetooth connection through the aluminum case.
As an alternative, you can purchase the K4 Pro but buy 3rd party shine-through keycaps and replace the stock keycaps that the K4 Pro comes with.