Yeah, I think 99 tents is less than 300 000 gil, right? I'm not sure, but I'm pretty sure it is.

Strategically, getting the villa is absurd. But, if you're a perfectionist and want to get everything in the game, or at least do everything and watch every scene, go buy the villa. It's something to do.

I'm not sure exactly how many battles this takes, but the quickest way to do this from scratch is to put an All materia on Cloud's Apocalypse, then fight battles in the Crater where that song called Renunion plays, and hopefully you have enough elixers. Before long, you'll master the All materia, then if you sell it, you can afford 4 and 2/3 villas.