Only getting the voltage up is difficult. +5V to +12V/-12V may be $28. +24V to +12/-12/+10/-10/+5V/-5V (with separate ground 12V away from the common ground) will be several cents. If the application is not meant to be portable, think rather about getting the input voltage scaled down to several different values than scale it down to 5V just to scale it up to 10V a moment later.