Summoner runs for Hate keys are exceptionally useless- since he... won't give you much else... in a million years.
Countess runs are okay for people... who really wanna spend longer(unless use maphack) teleporting there and finding mostly crappy runes from the countess and sometimes keys.
Destruction keys from nithilak(spelling?) are worth twice as much as the other keys though, and maphack isn't needed to get there very fast... but a really good character like a hammerdin with enigma is...
3 Keysets is/was worth around IST... tho any Torch you'd get after doing uber trist would be hard to trade for even a Mal(or for me it is anyway).. so I don't know what will happen to Key prices(though they should go WAY down)
Either way... ATM keys (at least on USEAST) are fluctuating in price. I personally do nithalak runs while trading Lem runes for each Dkey other people bring me.. then Trade 7-8 Dkeys for an Ist rune(and last time I checked... 7-8 Lem runes is NOT worth as much as ist) I made about 5 ists in the last 2 days doing this.