Mark Brodie/KJZZ

Light rail in downtown Phoenix.

The Phoenix City Council could scale back the multibillion-dollar tax hike that would fund transportation projects in the Valley. On Wednesday, the council will meet to consider the changes to the ballot initiative.

Supporters are not backing away from the tax increase, but they are looking at how it could hurt the bottom line of some Phoenix businesses. Specifically, those selling big-ticket items like cars, boats and jewelry. In response, Mayor Greg Stanton is asking the council to consider not applying the new rate to any amount more than $10,000.

Seth Scott, a spokesperson for Mayor Stanton, said this tax hike of $0.003 would amount to an extra penny on a $3 cup of coffee.

"Nobody is going to cross city lines to purchase a cup of coffee for one cent less," said Scott. "But when you start to look at large scale items — things that cost $20,000 to $40,000 — then people are going to shop from city to city," he said.

Scott said neighboring cities like Glendale have also set up their sales tax this way to stay competitive. But some council members, including Sal DiCiccio, disagree.

“This proposal is definitely rushed and no one has thought out the unintended consequences," DiCiccio said.

DiCiccio said this change would simply save money for people who have more to spend, "so the disproportionate share of the tax will be paid by the working class."

Exempting big purchases from the new tax rate would mean $700 million less in revenue for the Transportation Plan, which is only a fraction of the $31 billion price tag.