If that costs too much mana for you than you may need to manage your mana better. If you have more than one person dying and multiple people low, than yea you're going to have mana issues, but in that situation your group is doing a lot wrong anyway so your low mana isn't your fault. But if everything is generally fine and one guy dies because he got hit by something he shouldn't have? Yea, I have plenty of mana (and natural mana regen) for an insta rez - medica - cure - protect - and back to healing.