Almost $50,000.
I always make way more money than I need in Pokémon games, so I always spend it really liberally. I just bought like 50 or 100 of each individual item regardless of the fact that, other than Poké Balls and potions, I probably wouldn't even need to use any of them more than once.
Then I found out about the villa. :( If I knew about that from the beginning, I would've saved money the entire game and had a totally pimped out house! All I was able to afford was the PC desk.