Now is not a good time to buy polaris cards for mining. Period.
Wow, ok. Is there any specific reason for this? I have similar feelings due to hearing people selling these cards and moving to GTX 10x0 cards but have not found any specific explanation for this especially when it's very difficult to find these GPUs and their price is way higher.
They cost too much for what they do. Their value is very reliant on the value of eth. If you can get 570s at around $200 that's prob worth it.
If buying amd, you're mainly paying for the memory, not the gpu. So get lower end cards at or close to msrp. Not worth it to pay a premium for some high end turbocharged edition when you're basically going to suppress the core anyway.
i dont think it's possible to get 570s for around $200...