I keep getting side tracked and not responding.
Get a consumer card with lots of vram if you are doing ML. That is about your only requirement.
Anything second hand could be worth the money in the end. But I would spend some extra to get a newer card so you can use bigger models rather than getting a 300$ older card.
Edit: a Radeon 7600 has 8G of ram US$280. Plenty of space for those ML.