To fulfill your needs: 12MP camera, 16GB ROM, GPS, WiFi and so on. There are many choice for this. Followed are some budget smartphones around $160:
1. Oukitel K10000 smartphone: 10000mAh battery, 2GB RAM+16GB ROM, 13MP camera, GPS/A-GPS, MTK6735P 64bit CPU and Android 5.1 OS.
2. XIAOMI MI4: 13MP Sony camera, Snapdragon 801 quad-core 2.5GHz chipset, 3GB RAM, 16GB ROM, Android 6.0 OS and 3080mAh battery;
3. Letv Le 1s: 5.5-inch FHD display, MediaTek Helio X10 2.2 (MT6795T) chipset, 3GB RAM, 16GB ROM, 13MP camera, GPS
4.Oukitel k6000 pro: MTK6753 SoC, 6000mAh battery, Android 6.0 OS, fast charging, 3GB RAM, 32GB ROM, 13MP real camera.
Maybe you will be interested in one of them, just for your reference.
I've had an iPhone 5 for a while. It doesn't allow an easy GPS on/off shortcut, and the non-replaceable battery is coming to end-of-life. Ive searched for a website with filters for all my needs in one place.
Are there any (affordable) factory unlocked GMS Android smart phones available with GPS, WiFi, 16GB for applications, an SD card slot, hi-pixel (12mpx) camera, with a replaceable battery? Maybe I want too much!