Card for MAC (gasp)

[frodotheturtle]

so i just got myself into trouble and bought a 2009 mac pro. i was looking at graphics cards and realized the s**t storm apple recently created with mojave. it lists officially supported graphics cards on the apple upgrade instructions but the only good options are very specific versions of a 560 or a 580. i want price to performance so i was a little bummed about only getting to choose from 5xx but now I'm stuck between a lower performing card and something a little to expensive for my liking. Im looking for something under $100 (used) but that can still get decent performance and get me into mojave. If anyones used a 570 in this situation pls tell as i found several for cheep (mining).