Clerics just got an increase, and don't really need more. If you find you don't have enough mana, it's either your fault due to a bad build, poor mana management, etc. Or it's the party's fault, which is also partly your fault. If your party keeps making bad decisions, like zerging through traps, splitting up or any number of other things a bad party can do, sit them down and lay out some rules...
1) I am not your personal buffbot. If there's is something you want that I haven't already cast, ask. I'll do my best to decide on whether or not it's something you need. And if it's something you can/should get from a potion, you obviously don't need it because you didn't buy it.
2) I will do my best to keep you alive and healthy during fights IF you don't run out of range, around corners, behind pillars, etc. I fully expect you to top yourself off, remove your curse, drink minor restoration potions, etc. between fights.
3) I can't, and won't, Heal Stupidity. If I ask you to stop zerging, switch to a shield or change your tactics because I'm using most of my mana on you, please listen. You won't be the first, or last character that I've carried through a dungeon in my backpack.