OP here: Teknic Clearpath servos are considered good value and come in lots of different sizes/price points. Wiring them up could not be simpler, but know that you need a windows computer to tune them.
If you are comfortable with soldering, motor sizing, and python, you can pick up an ODrive control board and some sort of position sensor and turn almost any motor into a servo motor.
I've purchased a couple of these for UT CNC systems; definitely good bang for your buck, but that's if you need to drive a 1200 lb bridge at 6 in/s, and have $600 per motor to spend.
I ended up not using them because I found it was simpler, cheaper, and fit the mounts better to buy a pack of NEMA34 steppers and a few $15 dollar encoders. Seriously, spent maybe $800 on decent quality steppers/encoders/amps for 3 axes, where the ClearPath servos would have been $1600 for the same 3 axes, but wouldn't have provided position feedback nor allowed position localisation to be decoupled from the motors (which is the best way to do things in most cases).
I think it's hard to justify the costs of these types of motors unless you have some very specific torque/speed/spacial requirements that require them. If you're building a machine that is worth >$4000 per axis, then maybe, but if not, simple steppers are the way to go.
Ebay. That's by far the best place to spot really good gear for a small fraction of the sticker price.
The usual suspects for brands, personal favorite: Panasonic Minas series drivers + associated servos. Cheap, super reliable and available in just about every size that you could possibly want.
I've looked into this a few times and it always seemed like there is a huge abundance of servo motors, but the market for servo amplifiers seems to be tiny in comparison. I always suspected this is because the electronics of decommissioned machines are just scrapped wholesale. However, I am also wondering what people are doing with all these servo motors without matching cabling and amplifiers.
Good point, amps are a bit harder to get by than motors, but then again, there are plenty of them on offer. I only paid full price once for a set of servo amps and that was because I wanted to have a particular type for a very special set of motors (pancake servos).
How do you deal with the proprietary connectors on the motors? Replace them or only go for motors that come with stub cables? Proper replacement plugs probably cost about as much as a used motor... and most seem to be sold without cables/plugs. (Unfortunately it is hard to search for this stuff, because everything is "polluted" with model making servos)
