According to the Daily Mail, the unknown woman also has her own driver in addition to being surrounded by a bevy of security staff at all hours of the day and night.
"There are six security guards on rotation duties, for nine months," the source also said. "They have rented four different cars, and the surrogate has a driver.
"So with the rent on the house, expenses for the security staff and their wages - that's around NZD $2 million for the surrogate's safety. But of course, it's worth it - they want the best for her and their unborn baby."
It was first reported in June that Kim, 36, opted to go the surrogate route due to health complications during her first two pregnancies.
The reality television starlet was diagnosed with placenta accreta during both pregnancies, a potentially life threatening condition which occurs when the placenta attaches too deeply into the uterine wall, which could lead to severe hemorrhaging during labour.
UsWeekly was the first to report that the surrogate was pregnant.
TMZ claims the famous duo paid $62,000 for the surrogate to carry their third child, and the unknown woman must abstain from smoking, drinking or doing drugs during the pregnancy.
She is also banned from using hot tubs, hair dye and eating raw fish.
The celebrity news agency reported earlier this week that the surrogate is a married African-American college graduate.
Kim and Kanye are parents to daughter North, four, and son Saint, who will turn two on December 5.