You can spend $10,000 in no time.
It's 166 barrels of Smurf Berries! And it will be 5h and 20min of fun due to the $500/15 min IAP restriction.
(Also, and this isn't the reason for limiting it only to the App Store and iTunes, but Apple only has to spend $7,000 to give $10,000 due to Apple getting 30% of every sale.)