>>53266209>He was rich, why didn't just use his wealth to improve it?He did, he's mentioned to have financed a lot of things and that's how he became known as a philanthropist in Kalos.
However, he realizes no matter what he tries to improve, he cannot forbid time from going by and good and beautiful things to wither, because that's the true essence of the world: a cycle of beauty and uglyness, of good and bad constantly overlapping.
He grows obsessed with this concept and reaches the usual solution insane PokéVillains come up with: wake a Legendary up to delete/mess up the known world.
If the world as Lysandre knows it is bound by time to change, he has no other way to avoid it that destroy it and keep the nostalgic memory of how good it was (Y, which makes more sense for an insane individual like him imo), or force it to stay that way forever by crystallizing existence the way it is (X).
It's a stupid plan but average for Pokemon standards.
It would've been interesting if XY expanded it better.
The "you can save yourself if you pay an insane amount of money" part makes zero sense though and it doesn't even match right with how Lysandre's mind seems to work.
Wtf GameFreak.