The Keychron K4 has been awesome for me but slightly above your budget. Perfect time to start looking though as I suspect we'll see some sales come Black Friday. Has Mac function keys built in, subtle backlighting if you're into it, Bluetooth (with multiple device pairing), and a pretty good battery life. Some folks may like mechanical keyboards (others might prefer scissor switches or rubber domes) and it's a pretty deep rabbit hole, but here's something available off the shelf which is pretty good. You can buy some keycaps if you want it to look slightly different down the road.

There are also variations depending on your key switch preference, whether you need a 10 key, etc... The only thing I would mention is that I would avoid 'optical' switches as they have a tendency to trigger before the "bump" on blue and brown switches for me.

Edit: The Keychron K6 is in your budget if you don't need a 10key and want something compact.