Providing 3 phase 575 is not difficult. If you can bide your time, it is not even very expensive. As usual, it depends on your situation and what your plans are. Start with sorting out the 3 phase.
If you have (planning to have) a few industrial type machines (meaning 3 phase machines and each one having special considerations - such as multi-speed motors, several motors on each machine), then it is worth it to sort out a 3 phase source - for most people that will mean some kind of phase converter. The ubiquitous Rotary Phase Converter (whether purchased or homemade - many great plans available to make your own) is where a lot of people start. Once you have 3 phase the machine purchase options really open up. Generally 3 phase machines are going to be commercial, or even industrial quality. Being 3 phase may scare off some buyers and improve your purchase price (3 phase is getting to be so easy that the power issue scares off very few buyers). Once you have the 3 phase 240V power, then you can easily keep plugging in 3 phase “200v” machines (could be anything from 208v to 240v - don’t sweat it, just plug them in, at worst you’ll need to reconnect a control transformer). I suggest getting a 3 phase panel and setting up a small distribution system. I have a few machines wired in, and then others that I run off a cord with twist lock plugs. 3 phase “200v” is an extremely common power supply on machine tools.
There is nothing wrong with swapping to single phase motors, or using a VFD to provide 3 phase - oft times these are not difficult conversions - but it is work, and you have to do it for every motor: sourcing a motor, mounting it, adapting the drive connection, gutting the old motor controls etc. with a phase converter, the efforts are external to the machine (the machine manufacturer probably put effort into a system that works well, it is nice to leave it alone).
I have 3 manual lathes. One of them (an 11x20 Standard Modern, would have been an easy one for a motor swap) I have powered off single phase via a VFD (to get the 3 phase) - main reason to do it was just for fun. My cost was zero because I had a surplus VFD, the machine came to me pretty well gutted - it came to me at very low cost as a project machine). The other two lathes are regular geared head machines - it turns out that I rarely use the little VFD SM lathe. The VFD is not enough of a benefit compared to the advantages that the other two lathes have (every machine is a bit different). IMO the VFD is a minor nice to have - it is not a game changer.
Now to get the 575v, simply connect a transformer. It may be referred to as a ”step down 575/240V” - but no matter. A transformer works fine in either direction. I paid $100 for a used 6.5kVA transformer from an electrical equipment rental shop. It may take a bit of looking /patience instead of buying new. However, once you have the 575v sorted out, the purchase premium improves in the buyer’s favour. I now have 5 machines that are 575v 3 phase - most other buyers get scared off because they don’t want the hassle of sorting out the power. Cross that bridge and there are some great opportunities.
