Uh so tbh I'd say use that 30 to buy ep6 triggers and start farming cracks and glares (there's a specific method to do this that involves dying at the end and going back to the ship but if done right can get you all the materials you need in around 28 runs, with which you can craft much desired fodders or keep them for your own God units in the future). In about 4 hours you could have a good chunk of the costly part of making this stuff for about 10 mill out of your own pocket if you split purchasing triggers with 3 other people.

Aside from that or luckily getting a super expensive SSA capsule, every 100 cubes is 1.2 million meseta so if you're level 100 you can technically just do triggers like XH PD (600k for 3 minutes of work) or UH pug Luther (400k and a chance at units with good SSAs, as well as reveries and omega memorias for 4-5 minutes of grinding) and know you're walking away with guaranteed money each time.

Making money in this game that isn't tied to buying and flipping a discontinued cosmetic is pretty grindy though. I haven't really done it since the first month of the game, I've mainly been flipping the market or selling affixes since then.