I picked up a 2-1/2# cross pien at Home Depot last year for no more than a regular hammer. Other than that, ball pien hammers have seen the most use. I didn't have a forge with enough umph to reshape a hammer head until recently, so the hammers are still unmodified... won't be for long though.
I also plan on making myself a 1 to 1-1/2# diagonal pien hammers from scratch just to prove that I can.