I'm sorry to be "that guy", but I got my kage Gaara done very long way around. Did elite instance for kage Gaara daily for frags long before we got his skillbreak/trials, because I knew he'd get them. Once they opened, I spent my frags maxing 5-star kage Gaara's skills. I might have even overdid it, since I had plenty of frags left after.

I recommend using Trials for ninjas you don't have good way to get frags for, since that may be cheaper than buying their frags for max skills. I think plenty of people use Elite instances & Ninja collection for frags to get skillbreaks and later change for trials, if trials are better than breaks.

My personal opinion about your matter: +100 tries and not even any +1s? I woudn't call that bad luck anymore myself, if it happened to me.

Edit: Renji's idea of getting 1 or 2 skills to gold and then farming frags for rest should save lot of time, since it took me so long to get frags needed for full frag skills.