Don't use consumeables that disappear when you die... for learning a place like Kara you are likely going to die a lot and rarely will anything that you do make much of a difference.
Flask of Fort
Greater Rune of Warding (persists through death on your bp)
Sharpening stone if have them (persists through death on your weapon)
Cheap Stamina food --- emphasis on cheap.
Otherwise you are throwing money down the drain. If you are undergeared to start tanking in Kara, Ironshield or Greater Stoneshield pots can make the difference but the only fights that I think they make a huge difference is the prince and nightbane... and they add up if you are wiping over and over learning.
No reason to waste money on consumables if you are not the weak link in the chain (and honestly in Kara the tank is really only the weak link on the prince and nightbane - the rest healers or dps will be the real key to the fights).
The beast is getting hungrier.