Not only did the residents of San Francisco’s exclusive Presidio Terrace win back their gated street — they also get to keep their bargain-basement tax rate of $4.28 a year for the private roadway and sidewalks.

That works out to 12 cents a year in property taxes for each of the 35 homeowners who once again jointly control the street, now that the Board of Supervisors has voted 7-4 to rescind the city’s tax-default sale of the property to a South Bay couple.

Nullifying the city treasurer’s 2015 tax sale means that Tina Lam and Michael Cheng of San Jose will get back the $90,100 that they paid for the street in an online auction in 2015.

It also means that the street’s property tax — which went unpaid for 15 years because the city was sending the bill to the address of a long-retired accountant — reverts to $4.28 a year. Had the supervisors voted to let the sale stand, the property tax would have been $1,054 a year.

“That’s correct — it reverts back like it hadn’t been sold,” said city Assessor-Recorder Carmen Chu.

Future increases will be limited to the 2 percent a year allowed under Proposition 13.

The homeowners, however, will have to pay the $994 in back taxes and penalties that led to the property going on the auction block. The land also carries $345 in annual special assessments from the San Francisco schools and community college district.

Presidio Terrace homeowners successfully argued that the street, sidewalks and palm-lined green strips of their private enclave had been sold out from under them without their knowledge. And while they conceded they had neglected to pay their annual taxes, they blamed the treasurer-tax collector’s office for sending their bills to the out-of-date address.

The $4.28-a-year tax bill is “a steal, but there is nothing lawmakers can do about it,” said Supervisor Aaron Peskin, one of the four supervisors who voted against reversing the sale. “The assessment laws are the assessment laws in the 58 counties of California.”

Supervisor Mark Farrell, whose district includes Presidio Terrace, said that if there was any steal involved, it was the “bottom-feeding pirates attempting to extort and hold San Francisco residents hostage.”

And he noted that even if the city wanted to raise the tax, Prop. 13 would prevent it.

The Presidio Terrace homeowners association has held title to the private street since 1906. And while assessor records cover only the last three decades or so, there is no evidence that the property has ever been reassessed.

Prop. 13, which the state’s voters passed in 1978, capped residential tax hikes at 2 percent, starting with a property’s 1975 assessment. No reassessment happens unless a property changes hands.

Assessor’s records list the Presidio Terrace property’s value at $362. Establishing the true value would not be easy, given its circular configuration and easement rights that assure those living on the street can get in and out of their homes.

“It’s zoned residential, so it’s not like someone could built a casino or pot club on it,” Peskin said. “Still, it does have value.”

It’s safe to say Lam and Cheng saw more value in a prime piece of real estate than $362. Their lawyer says they’re thinking of suing.

Matt Dorsey, a spokesman for the homeowners, said the couple met twice with his Presidio Terrace clients several months back. Lam and Cheng said the property would be worth $18 million to $34 million “after it was converted to a parking lot and began generating revenue,” Dorsey said.

In fact, when we interviewed them over the summer, the couple floated the idea of using the street for parking — saying that if the Presidio Terrace residents weren’t interested in paying for parking privileges, perhaps some of their neighbors outside the gates would be.

Lam and Cheng insisted at the time that the property wasn’t for sale. Only as the two sides were headed to last week’s City Hall showdown did members of the Board of Supervisors suggest the homeowners reach out with an offer to buy back the property for $200,000, or roughly double what they had paid for it.

Dorsey says the couple’s attorney, Shep Kopp, countered with an offer of $950,000. But before homeowners had a chance to consider the proposal, Lam and Cheng “spoke directly to members of the homeowners association and told them the property was not for sale,” Dorsey said.

“And that closed the door for the final time.”

Kopp declined to discuss details of his last-minute negotiations with the homeowners. But he did have some choice words for Farrell, whom he described as “a craven lickspittle who is only too happy to carry water for his rich neighbors in Presidio Heights.”

“And it’s dismaying to see District Two represented by this opportunist who needs these homeowners to contribute money to his campaign for mayor,” he said.

San Francisco Chronicle columnists Phillip Matier and Andrew Ross appear Sundays, Mondays and Wednesdays. Matier can be seen on the KPIX TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call (415) 777-8815, or email matierandross@sfchronicle.com. Twitter: @matierandross