I couldn't help myself and started watching as much footage of Gold as I could, and this extended all the way to the end of the game. At the end, Wario, as always, tries running off with the cash when the others confront him about getting paid, and they all only make a small fraction of what Wario earned; most of which he spent on balloons, according to him. For reasons I don't entirely know of, I decided to sit down and count just how many balloons Wario must've bought.

I'm not trying to be super accurate with this information (and to be honest I dunno how many people will actually care :V), but I did think it was fun to try and piece together.

• There are 20 people present in the ending sequence - Wario, Master Mantis, Young Cricket, 5-Volt, 18-Volt, Penny, 9-Volt, Orbulon, Fronk, Mona, Kat, Ana, Jimmy T, Red, Ashley, Dribble, Spitz, Dr. Crygor, Mike, and you (since you're given a split of the coins, after all!). Lulu doesn't count since it's implied she rode back home after the fake credits roll (seeing as though she wasn't present in any of the group shots while the others were splitting up the pay).
  
• After the ending sequence, you're given "your share" of 10,000 coins. Since it was split equally, we can assume that Wario had a remainder of 200,000 coins when he initially tried to run off with the money.
  
• In the opening cutscene, he said he was giving out a grand prize of "10,000,000 coins." For the purpose of this calculation, we will assume that's the total amount of money he ended up with, especially considering he was never intending on handing it out, anyway. This means Wario spent 9,800,000 coins in total on balloons.
  
• The capsule machine costs 600 coins for one spin. Similarly, in Japan, a gashapon machine can cost anywhere between 100 and 600 yen to spin, and since Wario's always trying to squeeze out as many pennies as he can out of people, it makes sense that he'd go on the high end of the price range. Since 100 yen is (roughly) equivalent to 1 US dollar, this means you were given $100 for winning the game, Wario's pals split up $2,000 for everyone, and Wario spent the remaining $98,000 on balloons.
  
• In Wario Deluxe's stage, we see him riding in some balloons. Since they all appear to be bigger than his head, we can assume he bought jumbo balloons. Party City charges between $7 and $15 to buy jumbo balloons, and seeing as though Wario wants to save up his fortune and cut expenses wherever possible, we can assume he bought them on the lower end of $7 (or 700 coins) per balloon. $98,000 divided by $7 per balloon would mean that Wario bought approximately 14,000 balloons.
  
• To double check stuff and make sure we're being at least semi-accurate, we need to see if he could actually get off the ground! it would take roughly 3,571.42 balloons of this size in order to lift a human that weighs 50 kilograms, and since Wario weighs approximately 140 kilograms, this means we'd need 10,000 (or 9,999.976, if you want to be more accurate) balloons in order to get him airborne. We can assume the remaining 4,000 balloons are needed to lift up the basket and the toilet on Wario's head (or, as he would refer to it, his "crown").