In FFXIV, the process of Pentamelding is an extremely expensive venture. This means that instead of putting the standard 2 Materia into your armor slots, you need to add an extra 2-3, which depends on your choice.
The failure rate of this process is high, so you will likely lose Materia through this. But if you want to gamble, that's worth a try. IGGM lists what you need to know about Pentameld.
Before trying Pentameld, you need to complete a specific quest to unlock an ability - Melding Materia Muchly. You can do this by talking to Mutamix Bubblypots in Central Thanalan (X:23, Y:13). You need to reach level 19 with any Disciple of the Hand profession, starting from the “Waking the Spirit” quest, you can get it at F'hobhas (X:23, Y:13) in Central Thanalan. Melding Materia Muchly's quests can get you into Advanced Material Melding.
After completing the quest, you can wait until your character's job reaches the max level and gets the highest equipment you want to use. Then you have the opportunity to place the Materia onto your gear. If the item doesn’t say "Advanced Melding forbidden", you have the chance to add extra Materia beyond standard 2. You can try putting in more to add 2-3 Materia, but you may lose some Material with doing this.
Based on this, you can go to a high-level crafter to do this. They've probably gone through this process a few times and already have experience, especially if you don't want to meld the Materia into your gear. If you're taking the Materia to potentially lose, you should be good to go.
Anytime you need FFXIV Gil in FFXIV, you can come to IGGM to buy it. This will help you get good gear and weapons faster to deal with any difficulties. And with Endwalker in full swing, it must be a better option to buy FFXIV Gil, which allows players to focus more on the game itself.
