This has been a flogged-to-death issue for quite some time here.
IMHO, and with all due respect to Alembic, the OEM Alembic (G&G-sourced) HSC case they offer is overpriced for what you get. The problem is, as stated above, most Alembics can't fit in a std. case, so the custom sizes limit suppliers and raise cost. Add to the fact that Alembic buys in small quantities which results in higher costs. Since Alembic isn't in business to give stuff away, they have to add their mark-up and have to pass the cost on to us. What I don't understand is why we can't get a higher-quality case from G&G? They do make the OEM PRS Custom Shop/Private Stock leather-clad cases, which are much better than the ones we get from Alembic. It certainly shouldn't be a cost issue...who here wouldn't pay a little more to get a better case? I know I would! Having said all that, Alembic does make it a policy to contract from US manufacturers wherever possible, so they should be commended for not going to Asia for their case purchases.
In addition, my Series I was damaged by rough DHL handling when shipped in the std. OEM case. The case had the central latch busted-off and the neck finish cracked at the headstock when the thing was apparently bounced during handling. The OEM case is far from the best protection you can get for your expensive investment, IMHO.
FWIW, I'd go to Calzone or Anvil or (fill-in-the blank) ATA Flight Case manufacturer for my next Alembic case. They'll make you a custom case to your specs for around what the OEM HSC case costs. Calzone already has templates for most Alembic body styles, but you can easily make your own to ensure a custom fit. The ATA cases sourced by Alembic are decent, but the price is high and I had problems with the padding fitting/supporting the neck on my $9k custom Orion iV. This simply should not be on a case that took over 6mos. to obtain, costs $800-plus and was custom-made-to-order, but I regress.