Lex looked at how much MP he had spent. Due to the size of his many massive structures, the cost ended up being a lot more than anticipated. For example, just a single one of the 100 story highrises cost him 450,000 MP each. Adding 50 of them then cost him 22.5 million MP.
The colosseum, the city in the sky and the underwater city, as well as all the additional buildings in between them, cost him another 31 million MP. Obviously maintaining all these buildings would require sufficient staff as well.
Although the Inn automatically took care of maintenance and various other services, minimizing the need for actual workers, it was only minimized and not reduced. He hired 3000 more workers solely for the village, with the full expectation that he would need to hire more soon. Hiring them plus putting away their salaries for the next few months cost Lex another 11.7 million MP.