Heads up, there is a pretty steep learning curve.
Just like everything, there is the constant battle of cost, efficiency, knowledge, software, tooling, tool holders, cutter geometry and specifics etc... it goes on and on. Some of it makes a huge difference, some of it just shows up when one compares the not as good way to go against the better way.
Lathe or mill, there is a lot to learn. The lathe is simpler to learn, but wont cut tone boards for you (well unless you get an integrated type machine, but those are either horribly flimsy or have lots of zeros in the price tag and weigh tons.
Those little machines can do it. I know people who use the little sherline machines to make calls, and are happy with that. But the one thing I see that catches my attention there is the reason for the machine.... if its for repeatability... a lathe might be a good idea... if its for speed, then it depends on how good you are on a wood lathe and the material. On wood - I bet shy of a good heavy machine, an accomplished lathe hand on a wood lathe with the assistance of a little metal lathe could out run the hobby machines. The repeatability would be there for certain things, but not for others. So - there is one area of balance.
Of course price plays a roll... what ya got to spend? Remember, the lathe is only the machine... then comes tooling. Remember setting up to make calls on the wood lathe? Yeah... its likely to be way more than that to tool up a CNC of any type. A mandrel, collet chuck and lathe tools - maybe 300 bucks if you dont go cheap... some sort of custom contraption to be able to run more than one tool at a time on the hobby cnc will set ya back more than that most likely.
Get into the big machines (industrial) and the game changes severely... you got horse power now, bigger spindle through holes, and huge improvements in rigidity. But you also need 3ph power, a rigger to unload and place it, and so on... and you can get into tools... a holder for a profiling tool, probably 100.00, plus inserts are 5-10 each, and many places will only sell in boxes of 10. Then hole making holers and tools. A good boring bar is 130 plus... then inserts... again 7-10 each and only available in boxes of 10.
One thing that confuses me is you talk about getting a lathe, then say "I am wanting one of the vertical style to help do my inserts." - vertical lathes usually have a very different use than making calls... so that makes me think your talking a mill? If so... then you get to talk tool holders, can be cheap, can be 100 each... then the tool for them to hold... picking an endmill, then getting the feeds and speeds so it doesnt break, or melt, or burn, or chatter.
Once you battle all the tooling on either machine... you will need to be able to draw it out, so you can get coordinates, and then covert to g-code. The G/M stuff isnt bad... just memorizing what does what, but the positioning, that takes some accuracy, especially when you start talking arcs (G2 and G3) and if youre running a mill to do tone boards, you gotta map the board, then program it... which will be easier than an arc most likely, but take a long time to do by hand. (Ive done programming from scratch by hand and used CAM programs from a CAD drawing and the time investment is large - when going completely by hand) But if you dont understand the code, and a CAM program spits out something wrong and you get an error... and you dont know/understand Gcode... how do you fix it? Spent many an hour staring at a drawing and running a calculator to try and figure out an error on a arc movement... only to find I was off .0001 on a rounding error and the control spit it out.
I wont lie, its fun as all get out. I love this stuff. It turns my crank... but there has been a lot of trials and tribulations in learning, figuring out, and getting things where I feel they need to be. But I know a lot of people arent quite as picky as I am... so it may be easier for people who arent OCD about this kind of stuff like I am. I love tools and machines and toys and so forth... and Im the self-reliant type... but many a time have I realized that I was not that smart in bringing certain things in house... and should have just farmed em out.
If you have people who know machines and run them... might they not be a good source to check with as well? Since you can sit down one on one and they can see your part, know you and your abilities, and make some suggestions? Ask them about software too... most of the good ones, that actually make things more efficient usually are in the 4 to 5 digit price range. There are some free-ish types out there... maybe they would work? Maybe not? wont know til you try, but then you have the time in it, even if they end up not working for you.
In the end it all comes down to your wallet, your perseverance, your wants and needs, and the way you logic things out... can it be done? CERTAINLY! Is it fun? To the right type of person. Should you do it? All depends on you.
One last thought before I head in for supper-
I know some people dont like outsourcing... others live for it and hardly do anything in house except package things up... but you have to - at some point - put a value on your time. If youre going to end up making 500 calls over the life of the machine, then have (lets just pretend everything you buy is good quality and a deal and fairly cheap) 5k in the equipment side of things (machine, repairs, tools, tooling, electricity etc...) for the life of the machine... you have 10 per call already, plus material, plus time, plus learning time, etc... So whats your time worth? What if you crash the machine while youre learning? There is lots to consider... but sometimes you have to look at the forest rather than the trees.
It may be the funnest thing you ever do... could be the worst idea you ever had... only you can decide that. But there is A LOT to consider... So be sure to go in with your eyes WIDE open.
For example... one bone headed brain fart on my behalf took my lathe down for two months, and cost me 1800.00 in parts... used parts. So the unthinkable does come along. Glad I found used, cause new, Id have been in it for nearly 2x what i paid for the machine. But thats an industrial machine... and I had enough knowledge to diagnose and repair myself. Had I had to pay to have it done... oy... makes my stomach roll just thinking about it.
I am by no means saying "dont do it" - but you do need to realize... you dont just buy a stick of acrylic, a CNC lathe, stick it in the chuck, and press the green button.
Ill try and remember to check in here now and again to add to anything Butch has or answer questions.
Wade