A used GTX 1050 or 1050Ti should also be reasonable, if you get a model that does NOT require a PCIe connector.
The RX 560 4GB (1024-core version, not the 896-core version) is also worth considering - again, making sure that it doesn't require a PCIe connector.
HOWEVER, those should only be considered if looking in the used market. Their new prices don't make much sense considering the more powerful (but more power hungry) cards out there.
Now, if you do upgrade to a beefier power supply, then the RX570 should be considered. New, with full warrranty, they start at $120 (though I did once see an RX 570 model go on sale for $99.99, but that hasn't happened since late last year)