I made the Martin factory tour about four years ago. I had the strong impression that automation was used where appropriate, but that all the necessary/critical finishing operations were still being done by hand (frets/fretboard, bindings, etc., as well as the "finish" coating and polishing).

Those new Martins are awfully expensive though ~ I've been surprised to learn that, model for model, the new ones cost just as much as well-played-in vintage instruments.

Every guitar is an individual case, of course, but if you have a chance to try out, say, some brand-new D-18s for $2500 or so, you might also see if you can find a 50-year-old D-18 and give that a test-drive as well. The price will probably not be higher for the old one as for the new.

The lower-priced Martins are those with less pricey back-and-sides woods than the traditional favorites, rosewood and mahogany. There's a wood called sapele that is supposedly comparable to mahogany, and then there are laminates ("plywood"). As long as the TOP is real solid spruce (or cedar, etc.) and not laminated, these guitars are probably pretty good for their respective prices. I would assume that the same production techniques ~ automated cutting and assembly, handcrafted detailing and finishing ~ and the same quality standards, are in force as for Martins made out of more expensive materials.