Thanks for the pointer to the MAX13032. That also looks like a goo one.
I feel your pain with the seemly out-of-whack costs of some seemly simple items. BTW, have you seen the STM32F072? It has a secondary IO bus that can run at a different voltage level than the rest of the chip. Unfortunately, it includes the USB and SWD pins, so it's less useful than it can be, but I'm thinking about using that as an interface expansion MCU. I'm not so sure it would be a good idea for SD card, though, since I assume one should be able to boot from the SD card if it's attached to the SOC directly, but not if it's interfaced through an MCU.