I don't really think your idea is any better though if it's just one round of strikes. Then it's not even worth getting, no matter what the cost. Why bother spending even any gil when there's viable mining areas for free and ones you can use more than once per hour per node?

On the other hand, a good compromise would be nodes that you can choose to spawn whenever you feel like it, but it takes an hour to respawn them after they fade, which takes an hour to do like any node you find in the field. This way you gotta take breaks between gathering on a class.

As far as the rich getting richer... In a sense, that would be true, but the initial costs would make them poorer than the rest of us for a long time. In fact, the idea is that it's not something even wealthy individuals would want to spend money on, but a linkshell full of crafters and harvesters? They could all pitch in, so that grade 5 mining point that might take 5M and 50 gold ore to get gold ore available as an item, for instance, would be split between, say, 30 people, lowering the cost to something everyone can afford. And then they would all be able to use that house's mining points afterwards.

In fact, by wealthy individuals spending money on it, it causes gil to go out of the economy, which means that gil raises in value, which has the virtue of making everyone richer.

Of course, I'm not an expert on balancing, which is why I'd rather go on the side of broken and gradually make adjustments to bring it to balance rather than overcaution. Some caution is great, but too much and you wind up with another puppetmaster like in FFXI: so worried about it being overpowered that it became the weakest class by far, and it took years and years of updates before it gained it's own identity and became a powerful class, and even then the stigma remained. On the other hand, with something like 2H buff nerf, people whined about it getting nerfed for a couple weeks, others agreed that it was needed, and in the end people were content.

If my idea is broken, it's broken, but I'd rather we go too far and adjust it later than put in something that's not worthwhile at all and have a stigma of a system that sucks even after it's fixed.