In 2019, when mining became non-profitable, the network hash rate decreased from 300 terahesh to 150, then many good video cards were sold for $ 150-200, for example AMD Vega 56 and Vega 64. Check how much these video cards cost now.
We must be ready for a new sale of video cards.
I get some RX series at the time at a pretty good price. RX series seems the miners favorite from 2015 to 2017