It seems that keys and orgsets are screwed up for currency on east =(. The seller will want an um-ist for his keyset while the buyer only wants to spend a pul. hard to get a trade.
But for the original question, high runes are the real currency (orgsets equate to 2hrs). Besides that, um's are for the cheaper stuff (even ums are 1/2 hr) and puls for most good uniques. Pgems are only for the cheapest of stuff, but some deal in them (40 Pgems = pul).
PS. Among high runes, Mal and Ist (but not gul) have achieved hr status. The lowest to highest (in my opinion) are Zod, Cham, Sur, Ohm, Ber/Jah/Vex, Lo, Mal. I think i got all of them.