im running a carrion crown campaign and finished the first book yesterday so the players went shopping. one of the players asked for a ring that could do something along the lines of what the OP asked.
we usually have 4 to 6 players and i do not do the 4 encounters a day scenario. usually if the party is going into a dungeon, they are finishing that dungeon in a single ingame day or 3 depending on if they leave to rest up and etc, which usually means more encounters because the areas they clear get filled back up depending on how long they are away and how far they go.
anyways sorry bout that, i came up with a cure light wounds ring (1d8+5) for 3k. 1 time a day outside of combat which can use the touch up to 6 party members to heal in a single cast or a single target inside of combat.
big enough price for very helpful at lower levels but would pay itself off (compared to wands/potions) before wanting to switch it out for better rings.