I've owned high-end and low-end phones, and plenty of each. IMO, the best inexpensive phone is the T-Mobile LG Aristo. It is 4G-capable on ANY GSM network, afaik, goes regularly for about $100 new from well-rated eBay sellers (I paid $70 months ago), and is quite capable. T-Mobile has pushed 3 or 4 firmware updates over the last 6 months or so. Went to Android 7.0 recently. Works well with my 128Gb microSD card, unrooted, minor limitations. NoT a T-Mobile user? There's also a MetroPCS version. Most listings are carrier locked, a few are unlocked.