I used a hand held auger while building a fence for my sister. I didnt hit any rocks, but she has a hard compacted dirt/clay that made the thing useless. I tried soaking the holes with water over night and the auger would just spin on top of the dirt/mud layer. I spent days chipping away with a digging bar before I said **** it and bought a jackhammer with a spade shovel attachment. I picked up one of those sub $200
generic style demo hammers from amazon. It was fantastic. Even if it were to die out after the job was finished, it would be worth it. I only wish I had picked it up sooner. It would have saved me over a week in hard labor.
I dont use the thing very often, but if it breaks on me, I would probably fork out the cash for a bosch or something similar. Definitely a tool I want to have at my disposal in the future.