I believe Ethereum is going down so there should be a flood of used gpus soon enough but don't quote me on that. I don't think any of the companies are going to ramp up their GPU production because last time this happened and bitcoined crashed, miners weren't buying GPUs anymore so the companies had excess amounts of GPUs.
So just hold on tight I guess. Heck who knows, if you waited this long, maybe it's just better to wait and see if Nvidia will announce the gaming version of Volta.
PC Specs: CPU: 7800X3D || GPU: Strix 4090 || RAM: 32GB DDR5 6000 || Main SSD: WD 2TB SN850