Just thought I'd chip in here. I have the same problem. When I play with a flat pick my index nail gets worn down so I go to the nail shop. I get just one nail so i can pick the banjo. But I'm really loving the power and am contemplating getting my thmb and middle finger done as well. If you smooth the back end of the nail with an emery board the nail will last a long time before being filled in or replaced. This cuts down on the expense. Where I live all the women look at you really wierd when you come in asking for one finger nail. Maybe it's scary tto them that I'm a guy invading their comfort who knows.

Luke