I say don't worry because I feel as though, after 20 hours of play or so, that this scarcity of money was actually done intentionally. You get a glance at a lot of good weapons early on when you visit a city briefly and you have say, 9000 leafs (their GP) in your party, and the sword that would seriously buff your stats is 21,000. you might be thinking at this point like I was like "Wtf man? I'm not every going to have that much money to kit out every person in my crew!"
Well, yeah you are, and I think this was done intentionally so that you can't OP your team so early on.
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I'm playing on Switch but the experience will be the same on all platforms
I think that you are meant to have a glimpse of the stuff that you could get if you were flushed with cash but don't do something idiotic like hang out around the town doing like they did in that episode of Southpark where they fight trash mobs for weeks to have enough money to get the "good stuff."
Like in a lot of RPG's, that gear that seems so far out of reach will not only become something you can easily afford later, but you will likely end up discovering stuff that is actually better than that in other random chests you discover along the way.
When you are presented with a vehicle that I am intentionally not going to reveal what it is and it is 100,000 leafs, this seems like an astronomical and impossible amount of money to ever raise. Well, here I am about 6 levels later and I have not only purchased that vehicle, but I have raised several hundred thousand additional leafs without really even trying to do so.
There are some perks you can add to certain toons in order to boost the amount of cash you get per battle, but honestly, this boost really isn't all that meaningful.
One way that you can save money if you are super impatient is to just forgo outfitting all the members of your crew. There are 8 of you in total (hence, the "octo") but you can only have 4 of you in a party at a time. There is some level of micromanagement such as your healers needing different gear to boost their SP (MP) but what I do when I am swapping out characters is that the person I am taking out of the group, I remove all of their equipment and put it on the person that I am swapping in.
The only really important thing to remember is to make sure you re-equip them later because if you don't well, they are going to get killed rather quickly. I think that this will be obvious after the first fight though and isn't that much of a setback.
Later on in the game like say, past level 30, you can basically buy whatever the hell you want with impunity because you are going to be getting so much money from fights that you likely aren't even going to be paying that much attention to it.
I recall that in Hollow Knight I was really concerned about collecting all the money that I could in the start of the game only for that to become a completely useless additive in the game later on as you progress.
Perhaps this is something that is just in every single game.
Another way to make money if you really feel the need to do it is to put your thief in your party most of the time and level her up. That way, you can rock into every town and rob people of rare items that sell for quite a lot in the shop. This can be a much more effective way of raising funds than actual battles and if you kit her out properly, she can be a force to be reckoned with in battle. I wouldn't say that I find any of her battle-oriented thief skills to be terribly useful though but I am sure there are people out there that disagree with this.
There are a lot of guides and videos out there about how to make money fast using certain little tricks in the game and if you are hardcore and like to use exploits to make things happen then go ahead and do that. In the meantime, for casual gamers like myself just rest easy, you are not meant to actually be able to purchase these things the first time you encounter them.