While high-end smartphones may be getting more expensive, a lot of average consumers could do just fine with a mid-range phone. The Moto X4 is one such device, and the 32GB/3GB RAM variant is currently on sale from $140 at multiple retailers.
Amazon is selling the unlocked Moto X4 for $140 — it comes with Amazon apps built-in, but they can always be disabled. However, the bootloader can't be unlocked. If that's not your cup of tea, the Android One variant is on sale at Best Buy for $150 and has no such restrictions, and better yet, you get a Cricket Wireless SIM card activation kit and a $40 refill card with it too (that can always be resold). It would make a decent spare phone, and you can even flash an array of custom ROMs on it, like LineageOS.
The Moto X4 is still usable in 2019, even running Android 9.0 Pie. It chugs along on a power-efficient Snapdragon 630 processor and has an "isn't-that-adorable?" 5.2-inch screen in a classic 16:9 aspect ratio. Despite the low price, the phone is IP68 water resistant and remains unaffected by the notch and headphone jack restrictions of today's phones. You can check out our review of the phone here.