To be completely honest with ya, if you have 2 decent Pokemon around 67+, you can always spam train at Cafe Le Wow, and it's a pretty nifty source of income. Granted, you have to pay $100,000 to battle there per time, you gain a good amount of Balm Mushrooms which sell at a great price. Even if you are horrible at beating the Pokemon in the "correct" or "optimal" amount of turns, you will always make a profit, as the Balm Mushrooms sell for (I believe) 6,250 a piece, and you get a minimum of 16 per go around (16*6250=100,000) so you cannot lose money with this method, plus you still gain money from beating the trainers there. (Note: Apply Amulet Coin for maximum cash, and Prize Money O-Power if you have access to it, or EXP Power. Whichever suits your needs best.)
Here is the more detailed run about on what happens in the restaurants, but from experience it is a great method of farming levels, and money if done even half well.