Because you just NEED one of these now:
https://www.govplanet.com/for-sale/Tools-Monarch-Model-K-Lathe-Pennsylvania/5265286?h=5002%2Cmsg%7C62421%2Csm%7C0%2Cpstart%7C180%2CisAuc%7Cyes%2Cmf%7C1&rr=0.00532&hitprm=&pnLink=yes
There are some strong pros and cons to both power sources. VFDs have come way down in price thanks to the tech boom which should help close the gap. AutomationDirect is a good place to start for your needs.