Dual band vs single band.
Right, also a an extra router usb port. My point is that these two routers both do the exact same thing in an average household setting. The added features in no way actually improve your user experience, they're just added on to justify the 150% price increase.
Depends what you define as average household setting.
If the average household setting is in a single family home (as in the OP's situation) then a dual band router isn't going to offer much of an advantage unless they transfer so much data that they do want to use the 2.4GHz and the 5GHz carriers simultaneously (highly unlikely and definitely not the average case).
If the average household setting is in an apartment, dual band can offer a noticeable advantage - namely, if your neighbors' signals are on 2.4GHz but not 5 GHz, you will experience no interference from your neighbors if you connect to your router over 5GHz. Furthermore, even if your neighbors use 5GHz, there are more wifi channels allowed by the FCC at 5Ghz than at 2.4 GHz.
Here's one example. In my building, which is only 3 stories high and quite a few apartments wide (so not even that dense, it isn't a high rise), I see 13 2.4 GHz networks. all the networks except one are thankfully using non overlapping channels (1, 6, and 11). Some jerk is on channel 3.
Whereas on 5GHz, there is only one other one, and I set up my 5 GHz network to be on a different channel so I have zero interference.
I ran these tests with my phone.
At 5GHz, I got wifi speeds of about 100 Mbit/s
At 2.4 Ghz, I only got wifi speeds of about 30 Mbit/s