I wouldn't recommend you buy used presses ...unless you really know enough on how they operate ...to know if they've been "Bubba-Fied" or not...
Your investment in a good press....will last you a long time / and I think you've picked a good caliber in .45 acp to begin on ...its a very strong case - and easy to load - with a lot of powder, bullet combinations.
A single stage is fine....but so are some of the entry level progressives. Attention to detail - is required - in reloading ...and a single stage isn't inherently safer...in fact the tedious repetition / can make it more dangerous because it may take an hour or more to get a single box of 50 rounds ...but if you want to start on a single stage like the RCBS Rockchucker or some kind of a Turret operation ...that could work for you for awhile.
I like Dillon equipment...and their entry level press is the SDB. It uses proprietary dies...its progressive, with auto indexing...and will handle only handgun calibers. Some guys use them forever...some want to upgrade....but in good condition, if you take care of it, its also a press that is easy to sell used...as you consider moving up to a Dillon 650 or something else.
I like reloading ...and it is a major part of the hobby ...but I like it a lot more when the press gives me 800 rds an hour rather than 50 rds in an hour...( none of us have too much time on our hands ) not even if we're retired, and I am, but I'm still busy...