Its personal as everyone says and the worst guitar I played was a Gibson Les Paul Custom belonging to a fellow band member. I was playing an old Epiphone Les Paul Custom (it even had the same headstock and split diamond headstock inlay) and even he agreed my Epiphone was a better guitar - played better, sounded better and sustained for days so I do understand that not all 'cheap' guitars are bad and that not all expensive guitars are great.
Over the years, I have tried 'expensive guitars' - the Parker Fly when it was new, a fair few Gibsons but a lot feel good but not 'expensive'. As a fan of the Les Paul sound and as someone who was more accustomed to a Les Paul layout, when I finally had the opportunity to buy one - it seemed more sensible to spend that much on something I was more familiar with, something with a fixed Bridge as I hadn't owned a Trem, I tried to find the 'one' Gibson Les Paul. However I could not find one that felt, sounded and played great in the colour I wanted without any imperfections - regardless of how 'small' or inconsequential the 'flaw' was. One of the ones that I thought sounded the best, had a small gap in the neckpocket - you could get your nail into it or use it as a pick holder. The neck joint was often the biggest issue where the glue that squeezed out wasn't cleaned properly or wasn't taped up properly so the stain bled. I could go on but I am sure you get the picture.
Once I picked up a 594, it felt amazing, it felt expensive. Everything was finished perfectly and i much prefer the faux maple binding to plastic on a Les Paul around the body. I know that Nitro has its advantages but also wears quicker and the quality of the maple flame is definitely not AAAA or AAAAA (considering a non-10 top has much better flame). The neck on my 594, whilst not satin or nitro didn't feel sticky and that neck felt like I had been playing it for years, felt broken in. Every fret was perfect and the Double cut made the neck and the weight feel much better than any Gibson. Obviously a 594 offers locking tuners and the open back oozes quality. The knobs are so smooth and easy - no resistance at all and the switch felt better to me too. Before I plugged it in, 1 strum and I was sold. It rang and rang - maybe that was the Brass saddles and being thicker than a LP - but it felt more resonant. Whilst I wasn't interested in other colours, a quick look over and strum of an alternative told me it wasn't a one-off, that my 'one' wasn't the only 'one' and that I could have picked any and that could of been the 'one' such was the consistency. Therefore I felt confident to buy the 594 in the colour I wanted.
If I have to pay a bit more for that quality, for the extra time taken to ensure the guitar is 'perfect', that it passes the QC check to move on to the next phase of its build to ensure that by the time it came to be in my collection it was faultless, then I am willing to pay that bit more. Maybe if I had been lucky in my Gibson search, I would of bought that instead and may not of bought my PRS 509 'superstrat'. I would still of bought a Custom 24 because I had wanted one for over 30yrs. The quality and feel of that 594 though and the fact that I can order a PRS online to ensure I get the colour I want without worrying that its not the 'one' because they are so consistent.
Everything feels quality and the tone too sounds expensive. I know that may sound funny but play a US made Custom 24 and an SE Custom 24 - not that the SE sounds bad, far from it but the Core sounds better. I do agree that its not 4x better as the price difference would seem to indicate but it does sound better (to me). All those things add up and it seems like you have a big premium to get that 'extra' something that a Core PRS gives.
Once I had my first core PRS, nothing else seemed to match up, other than another core PRS. That quality and feel is addictive and why 1 became 2, became 3 and so on. Its why I am prepared to make sacrifices to maximise my saving potential for months to buy another core. Others may feel different but all I can do is speak of my own experience.