CPU/GPU mining of bitcoin has been irrelevant for years. See here:
https://bitcointalk.org/index.php?topic=1944976.0ASICS miners are the only way to go now. Check the hardware threads for S9, T9, R4, A6, A7, and Ebit. Once you wade through all that, you should know if you want to jump in.
Thanks for this.
So with a 15k budget one should simply buy 6 S9’s?