I'm not having problem with money at all, but I just got to high rank and haven't upgraded anything there yet. Due to previous plays though, I didn't mess around with any other weapons other than Great Sword and Long Sword, so I was very focused on my weapon upgrades. I rocked the Pukei armor for a majority of Low Rank and finally switched things up in the last few hunts and only used Armor Spheres to upgrade my armor for the last two hunts with Diablos/Rathalos.
Going into High Rank I already have a set of desired skills I want to complement my Great Sword, so I won't mess around too much making random pieces. Its only been out for a week so there are not a lot resources out yet, but in previous games that had some pretty bad ass skill calculators that you could punch it your desired skills and it would spit out possible armor/charm combinations.
One thing to keep in mind, it's a good not just to have your battle armor but also put together a set of armor specifically for resource farming. In the higher ranks you start consuming a lot more resources since the quest box is empty starting at High Rank so you can't rely on the EZ Rations and First Aid Meds. So going out and getting extra resources from plants or an extra swing of a pick ax really pays off.