OP, be sure this is what you want. The opportunity costs for a PhD are huge.
It’s usually 5-6 years for the degree, then you’ll have to do several years as a postdoc making peanuts. Even back in the 90s it was common to do two postdoc tours. After that you may find that tenure-track academic jobs are scarce (and still don’t pay all that well). In the private sector, jobs often require a very specialized skillset (and also don’t pay all that well).