HARVEY, Ill. (CBS) — A woman’s dream of buying her rental home was crushed after a suburban property tax bill skyrocketed.

CBS 2’s Tim McNicholas asked an expert what future homebuyers should look for, so they don’t get surprised with a big bill too.

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Joyce Henderson drives for both Amazon and Lyft, and she will also start a third job once Instacart completes her background check.

“I need the extra money, obviously,” Henderson said.

On top of all that, Henderson is a mom.

“I need the extra money because I’m paying ridiculously high property tax right now,” she said.

Henderson entered a rent-to-own agreement earlier this year for the house where she lives in Harvey.

She pays the mortgage and taxes and raises her young son, Jason, with the goal of someday buying the newly-remodeled house.

But now?

“Obviously, I won’t be able to buy it if the taxes are that high,” Henderson said.

Cook County records show the tax bill the past few years was about $2,500.

But the 2020 bill – the first bill since Henderson moved in – more than doubled to $6,500.

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That is because Cook County Assessor Fritz Keagi’s Office reassessed the property value from $65,000 to nearly $111,000.

Kaegi’s office defends that assessment in an email to us — pointing out that the home sold in early 2020 for even more than their assessed value:

“The tax increase is due, in part, because this property owner did not receive a homeowners exemption in 2020. Our office fixed this issue in October and she should receive a refund from the Treasurer within the next 2-4 weeks in the amount of $2,549.

“In addition, all properties in the south and west suburbs were reassessed in 2020. This home last sold for $127,000 in early 2020. Our assessment valued the home at 110K. Assessments should be in line with market prices. In this case, we are in line with what the homeowner recently paid for the property (in fact, we are a little lower).

“The average homeowner in Harvey saw an average assessment decrease of 14.5% and an average tax decrease of 11%. So this situation was atypical of other property owners in her area.”

“What are they trying to gain by raising property taxes, especially that excessive?” Henderson said. “There’s a lot of other vacant houses out here. I guess they just want another vacant house.”

Christopher Berry, a municipal finance professor with the University of Chicago, explained what the issue is.

“That means the old valuation was really way too low,” he said. “One of the facts about Cook County, sadly for the past years if not decades, is that the property valuations have been so bad – they were so out of whack, the values – that as the new assessor is trying to correct them, sometimes it results in really big changes in the value.”

Berry said prospective buyers should research not just listing prices but the county’s assessed values – especially as the county continues to reassess.

“If I were in the market to buy, I would probably wait to see the next round of assessments, meaning the assessment done under Kaegi,” he said.

Henderson’s landlord told CBS 2 he’s surprised by the spike too—and he worries he might have to foreclose. They plan to appeal in January.

“I just started doing this,” she said.

Until then, Henderson is trying to pay the bills however she can.

Harvey has the fourth highest tax rate in Cook County. But as noted above, when it comes to property values, the Assessor’s office says the average Harvey homeowner actually saw an 11 percent decrease.

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We asked the Assessor’s office why Harvey has such high property tax rates, given that it is a largely low-income area. They responded:

“Property tax rates are high in Harvey and other low-income areas because of a lack of state funding for education and an eroding tax base due to out-migration of residents and a lack of commercial properties. A lack of state funding for education requires municipalities to raise its property tax levies to pay for schools and other essential services. The erosion of the tax base puts more of this burden on residents and small businesses.”

Tim McNicholas