I personally have been using Xiaomi phones for the last few years. My Xiaomi Redmi Note 3 cost just $130 in 2015, had a Qualcomm Snapdragon 650 SoC, 2GB of DDR3, 16GB of storage, aluminum body, 1080p screen, 4050mAh battery. That had an SD card slot, but was unfortunately limited to 32GB cards.
My new phone, the Xiaomi Mi6, came with the Snapdragon 835, 6GB LPDDR4X, 128GB UFS 2.1 storage, ceramic back, and it cost just $430. It doesn't have an SD slot, but with 128GB of storage I don't really feel I need it. As it was on sale, that was the least expensive model of the phone available too.