In Chapter 9, you will be fighting a bunch of enemies that drop Credit Chips and its more expensive incarnations. FARM THESE PEOPLE.

Money is a bitch in a half to gain in this game cause the only things that give good money are the super rare metal items that give massive weapon XP or the even rarer item evolution items. Never sell either of them.

In terms of how weapon leveling works, there is an easy trick to it. Organic items, like claws, eyes, horns, and scales give little XP but raise the chances of getting an XP boost for other items. Inorganic items: Circuits, electrodes, power generators, and metal items, give significantly higher XP than inorganic items but they also lower the XP boost affect. So basically the strategy is to fill an item with organic components to raise the XP Bonus to 3x and then unload a ton of one of the inorganic items to get a huge XP boost from the initial 3x boost. Depending on the item you use, it can be knocked down to 2x to 1.5 boost after the initial experience.

Now here is the obnoxious thing, this can be done fairly easy thanks to the shops since one shop sells a few organic items that quickly raise the XP Boost and another shop actually sells most of the best XP giving inorganic items in the game. The catch? The inorganic items are horribly expensive and buying up 99 of the organic items it tough on a wallet in a game where gil is very hard to come by. Even worse is the fact that with the exception of the type of items I listed in my second paragraph, most of the other items in the game sell for crap so trying to sell off all the unneeded items is not going to net you enough gil to keep this operation going.

This is why, if you ever find enemies that drop Credit chips, Bomb Cores, or variations of either, you need to farm the hell out of them cause raising weapons levels and getting the second and final tier forms is an act of tediousness. Let alone even thinking about raising accessory items...

And no, it does not get easier as the game goes along, very few of the common enemies in the last chapters drop anything of value until you get to one farming spot in Chapter 12.

Another thing to point out is that raising weapon and accessory levels actually factors into the times needed to get 5 star ratings in battles. Basically it works like VIII where leveling your equipment and characters makes getting 5 star ratings harder.