Healer DPS in 8 person content is just as much a function of how good the other healer is as it is how well you heal/dps. That being said, when I started SCH in 2.X I know I just set small benchmarks for myself, and then just kept trying to improve. My initial goal was just 100, which I felt was a contributable amount. With better gear, you may wanna start at 200. Once you start thinking that way, you continue to find small cracks where you can get 3 Cleric Stance casts off. ANd certain fights, like Ravana, are very Healer DPS friendly.

But I will re-iterate it really is about your other healer as much as you. For instance, in T10 I would often get to about 300-350 - but that's just because all I had to do was Adlo preys - the WHM did all of the healing.