Couple things.
1.
@pauloqs : Recessing the back plate is not such an upgrade that it would affect the entire pricing characteristic of the guitar. Probably more influential is American vs. import pickups and parts, which is why the S2 Custom is more than the S2 Standard, and the CE with all American parts is more than the S2 Custom. Above that most of what you get are mainly aesthetics such as deeper body carve and prettier finishes, perhaps some premium woods for the connoisseurs out there. After all, the core guitars at a $1500 extra premium have the same pickups among other things as the CE level.
2. Recessing the backplate is such a tiny inconsequential detail. Is it something you ever see or notice when playing? For me, I could care less if my S2 Standard has a recessed back plate or not. It doesn't make any difference to how the guitar plays or sounds.
-k
There are things that affect price directly through cost, and yes cost contributes to price (price is a function of marginal cost in every economics text book). For instance, a solid neck with glued in headstock and heel, like CEs and S2s, is cheaper to produce than a one pierce neck like the Core, because it generates less material waste. The S2 and CE production process allows for more necks from less wood compared to the Core. Therefore it is cost cutting and some would argue that is inconsequential regarding the performance of the instrument.
As for the pickups, it is just cheaper to produce them in Asia. Labor cost is lower. Pickups are cost cutting measures.
Hardware, same thing. I just like to point out two things, just because people get confused all the time. 1) The tuners are not SE tuners. They are similar to the phase II locking tuners (not the same, but very similar). 2) Only the guitars with tem bridge share the bridge with SEs. The ones with fixed bridges share the same bridge as Core fix bridges.
There are things that are on S2s and CEs that, I agree, are inconsequential. For instance, why not use the SE pretend pearl birds? Instead they use a opaque plastic for the bird inlays. Why not use the CNC carved top similar to the SEs? Recessing the back plates could be done on a CNC without affecting the marginal cost (cost per unit), at least significantly. Why not do so? Because it affects the perception of the product.
If you spend enough time with an S2 or a CE, you could reach the conclusion that in terms of feel and comfort, the upgrade to a Core is fairly small. Not because Core aren’t worth it, but because S2’s and CEs are that good. They need to cause an immediate impression the they are not at the level of Core guitars without affecting the playability of the guitar. One was to do this is through things that are inconsequential. Like, for instance, the recess of a back plate.
The OP is not the 1st person that I’ve seen mentioning the non-recess back plates. I’ve seen a few gear reviewers mentioning it. Some even suggesting PRS to recess it because it felt cheap (reviewer’s word not mine). I think that’s the point. It emphasizes that Core are top of the line luxury guitars. If you can afford one, you should get one (those are my words). And you need to reach that conclusion in the first few minutes you try one for the first time. These small inconsequential things add up and they do matter.