You got nuthin'. The only rich kid in my childhood neighborhood had his head up his bunghole and wouldn't lend us any mud. We had to buy the water, rent the dirt, and mix our own. Then when the sun came out and dried it up, we had to buy more water and mix it again. At the end of the day, we had to return the dirt. Come to think of it, the rich kid's father was the water vendor...
At least you have mud and water to play in, when I was a kid we had to borrow mud from the rich neighbor up the street!