The city has spent $104 million and set aside $32 million more this year to relocate residents west and north of the airport to separate them from noise and make room for airport expansion.
To date, the city has purchased 389 of the 1,473 properties it plans to buy, The Arizona Republic reported. It plans to buy 1,100 more.
But some, who are unaware of the program, are still moving in or building homes in the areas the city wants cleared out, the report said.
"My concern is that someone pays so much for a house and finds out it's not worth what they thought its value was," City Councilman Michael Johnson said.
One elementary school, Ann Ott School, closed in 2005 after relocations began, but another, Silvestre S. Herrera School, expanded from 550 to 775 students, partly to absorb the kids with no school, the report said.
Nieves Morquecho, 93, said he was not inclined to move just yet. "Maybe in a few years," said Morquecho, who has lived in his home since 1936.