Since you are just getting into machining, I would not go the used machine route.
1. You wouldn't know "what's under the hood" (neither would I). There are too many potential gotchas.
Many folks on this forum with years of experience seem to have no problem rebuilding lathes, mills, etc. The main difference IMHO is that you need a working lathe and mill to rebuild a second lathe or mill.
2. I have a Griz G0602 and am very happy with it. I did pretty much disassemble it (as suggested by many forum members) and really learned a lot about it, in addition to using a LOT of Simple Green. Now if there is a problem, I can find and fix it because taking stuff off the second time is much easier and quicker.
The other plus with most of the imports is the amount of "stuff" that is included with the lathe. Grizzly pretty much standardizes on including 3 and 4 jaw chucks, dead centers, steady rest, follow rest, etc. But, as has been said here, you will need a lot more stuff to get up and running. At a minimum, a 0-1" micrometer (and maybe a 1-2" also). Digital calipers, tooling, tailstock chuck for drilling and reaming. If its in the budget you might add a Quick Change Toolpost, grinder, etc.
My mill was about the same price as the lathe and also requires tooling, collets, a decent vise, etc.
As a guess, I've spent about as much on the "other stuff" as I did on machinery. This is not to scare you off, but more of a reality check. Again you don't need everything a once and you can make many of the tools that you need (great practice).
Ask questions here. I constantly amazed at the amount of knowledge that is freely given. I've learned most of what I know (6 months experience and counting) for this forum and Tubalcain 's videos on YouTube (he's Mrpete222)
Best
Stan