Are you done with this year's spring cleaning? Amazon sure isn't, as evidenced by its continuing markdowns on Prime Exclusive smartphones. The Moto G6 was first discounted to $170, and then to $140. The Moto X4 too dropped to $130 a few weeks ago and is now marked down another ten bucks to $120. That's a lot of phone for not that much money.
The sale is on the 3/32GB variant of the Moto X4, which has a 5.2-inch 1080p display, a Snapdragon 630 SoC, an NFC radio (unlike the Moto G6), and IP68 water-resistance. We reviewed the phone when it launched in 2017, and found the then $400 price-tag to be the primary problem with an otherwise solid mid-range device.
Being a Prime Exclusive device, you won't be able to unlock the bootloader, though that shouldn't be a problem for most, as the phone is already on Android 9.0 Pie, and doesn't have a heavy skin bogging it down.