Seems to me like the most cost effective, longest lasting auger would be an old jiffy. You just have to be careful who you buy it from. If you find one that was owned by a responsible adult and was well taken care of, it will probably have many years of good service left in it and be half the price of pretty much any other power auger. I don't know how many older guys i know that still have their first tiller handle jiffy and still use it regularly. Several of these guys are retired mechanics who took meticulous care of their things and it shows. You might have to know/learn a thing or two about 2 stroke engines, but that never hurt anybody.