Motorola F3 Unlocked Cell Phone (Black) for $19.99.  Shipping is $2.99, so the total comes to $22.98 shipped. Here is a screenshot for your reference.  It may serve well as a basic budget phone or a backup phone.  It works with both T-Mobile and AT&T SIM cards.  Alternatively, it is also available at Amazon for $19.99 with free shipping on orders over $25.  Most places have this phone for about $34.