More than two dozen people slept in tents or their cars Monday night in order to snag first dibs at one of dozens of home sites being offered for sale in McKinney Tuesday.

“Because we’re crazy, that’s why,” said Mike Russek, who is moving his family from St. Louis for his job with Southwest Airlines, when asked about what others might think of his efforts. “No. We’re doing it because we want the premium lots here. And it’s first come, first serve.”

The homes will be built as part of phase two of the Prestwyck development in northwest McKinney, just south of Highway 380 and east of Coit Road.

Sree Annavarapu is 6-months pregnant with her first child and camped out in a tent all night.

"It is tough, but you need to sacrifice if you want something really bad," she said. "And I want it a lot for my family."

Lot buyers tell NBCDFW developers said the first 10 people to buy a lot get free upgrades totaling $3,000, but not everyone cares about the upgrades.

"I'm camping out not because of the upgrades for the home you buy, but because of the lot they're giving. It's a corner lo, I already have it picked out, I don't want anyone to take it." said Annavarapu.

There are 83 home sites available for sale as of Tuesday morning, according to Lisa Lawrence of First Texas Homes.

The lots are expected to sell within approximately 24 hours of them being offered, Lawrence told NBCDFW.

Russek was second in line for Tuesday’s sale.

“Number one” is a man camping on a cot laid out at the front door of the First Texas Homes business office.

Mike Russek will spend Monday night in the back seat of his rental car.

Local real estate agent Connie Durnal, from Redfin, came out Monday night offering water and refreshments to the campers.

She said she did not see a single crazy person in the crowd.

Instead, Durnal said these eager buyers are smart. And it is the real estate market in McKinney, and the greater Collin County area, that is crazy.

“I recently wrote an offer on a house that had been on the market for less than 12 hours. There were 22 offers on the home,” Durnal said. “They fly off the shelves."

Construction is expected to start by the end of the year and home buyers hope to move in by the end of July 2016.

According to the U.S. Census Bureau, among cities with a population of 50,000 or more, McKinney is one of the top 10 fastest growing cities in the United States. McKinney came in No. 7 with a 5.1 percent increase in population between 2013 and 2014.

Nearly 157,000 people call McKinney home.

