It seems like using guides has caused your confusion. Since this is an online game which evolves over time I think it's best to avoid using guides unless they were written within the last few months (latest patches). There's nothing about the current dol/doh gear progression that take weeks to grind through. If you cannot afford the best gear and aren't a crafter, maybe a crafter friend could help you gear up at a lower price than the marketboard. You could also try melding materia onto the cheapest lv70 gathering gear to give you leg up in the mean time and see if you can earn gatherer's scrips currency. Avoid referring to collectable rotations written before 2017 since one of the actions had its GP cost and effect increased.