70 fights on Ifrit sounds reasonable, yeah. Let's say each time is a speedrun, so <10min, that alone makes 700minutes which equal 11h40min...this sounds fair for Ifrit. If you count the downtime of 15min between each fight and the taper farming, that easily keeps you busy for a while.
If Nut charms are 100% as well, I'd tone that down from 20 to 15 Nuts for a weapon, since the fight takes longer than Ifrit and the weaps are not really "better".
If Garuda is around the corner, I'd be ok with taking 20 tokens for one weapon for the beginning, just reduce it over time with upcoming patches to make it more accessible.