Paying $100 more for mmWave is ridiculous. That's a 15% price increase for something that most people don't need or care for. The fact that you can't buy the non-mmWave version in the US is what makes this a really bad decision. The same is not true for the 4a 5G, which is $500 on the Google Store without mmWave, but has a special $600 Verizon-only version you can get with mmWave. So I have no idea why they didn't do the same for the Pixel 5. Instead you are forced to buy the mmWave version even if you're getting the device through Google Store and will never use mmWave.
Meanwhile here in Canada it's $800 CAD ($600 USD), so I'm happy I got the phone for a great price. That being said, if you don't care for 90hz display, wireless charging and waterproofing, 4a is definitely a fantastic deal at half the price.