Glow Beauty Inc. knew it was holding solid gold, and it wasn’t afraid to charge for it. On Tuesday it was asking $348 for four plastic bottles of Purell hand sanitizer.

That included free shipping, mind you. And the bottles were 40.5 ounces each. Still, buyers on Amazon were not impressed.

“Outrageously expensive, but needed for a patient waiting room,” one commented on the seller’s Amazon page Tuesday. “There’s a fine line between gouging and supply and demand.” After questions from The Post, the seller said it was removing the listing.

Widespread fears about coronavirus have caused acute shortages of hand sanitizer, creating a cottage industry online: Purell speculation. Amazon has been awash with sanitizer arbitrage, as third-party sellers hawk their remaining supply at premium prices.

“Village Pharmacy and Boutique” wanted $400 for a case of 24, 2-ounce bottles on Tuesday. “Collectible – Very Good,” it said of the cargo’s condition. That made an offer from a different third-party seller look like a steal – $229 for a dozen 8-ounce bottles “with Aloe and Vitamin E.”

Sellers were also active on Facebook Marketplace, where an 8-ounce bottle of Purell was priced at $40.

Amazon last week said it was cracking down on third-party vendors that are trying to profit from the coronavirus frenzy. But some sky-high listings continued on Tuesday.

“There is no place for price gouging on Amazon,” spokeswoman Cecilia Fan said by email last week. “We are disappointed that bad actors are attempting to artificially raise prices on basic need products during a global health crisis and, in line with our long-standing policy, have recently blocked or removed tens of thousands of offers. We continue to actively monitor our store and remove offers that violate our policies.”

Amazon didn’t provide further comment Tuesday on sanitizer pricing. In an emailed statement, Facebook said “sellers are responsible for complying with local laws, which include those related to an emergency.” Some states have laws banning price gouging during a crisis.

California Gov. Gavin Newsom was not impressed by the trade. “Seriously, @Amazon? These prices are absurd,” he tweeted on Tuesday, sharing a screenshot of a few high-priced Purell offerings.

A Baltimore-area seller on Facebook Marketplace defended his $40 asking price for an 8-ounce bottle. “I’m a poor guy with 4 children I’m just taking advantage of situation trying to make a little extra money for my family,” he wrote in an exchange with The Post.

He said he had “more than one” bottle to sell, and that he’d bought them easily at a store, insisting the sanitizer was currently available at some pharmacies and grocery stores. “Just the online people going crazy,” he wrote.

Despite his luck in finding sanitizer he could resell, retail shelves in many parts of the country were stripped bare.

CVS and Target stores in Washington, D.C., have been sold out of Purell and other sanitizers in recent days. A Bed, Bath & Beyond was cleaned out Saturday, after one woman bought $86 worth of purse-sized bottles, according to a cashier who would give only her first name, Shanee.

A Target employee who fulfills online orders at a Richmond, Virginia, store said it was “dead out of hand sanitizer.”

“One customer ordered 60 three-ounce bottles,” the employee said. “That was literally all they wanted.” Local media and Twitter users in other parts of the country also reported empty shelves.

Target, Bed Bath & Beyond and CVS didn’t immediately respond to requests for comment Tuesday.

Target’s chief executive told investors on Tuesday that coronavirus-related fears had led to “aggressive shopping” at its stores, though he did not address hand sanitizers specifically.

Gojo Industries, the Akron, Ohio-based company that makes Purell, has “increased production significantly” and has employees working overtime to deal with booming demand, spokeswoman Samantha Williams said by email.

Gojo said it became aware of the coronavirus in December and began increasing production in January, before there were any reported cases of the illness in the United States. The company’s factories – two in Ohio, one in France – have been running at full capacity since.

“We have experienced several demand surges in the past during other outbreaks, and some have gone on for many months,” Williams said. “At this point, the aggregate increase in demand is still below historic levels. That said, orders have increased very significantly in the past several days.”

The sanitizer speculation isn’t limited to Purell. On Amazon Tuesday, two different third-party sellers were offering a two-pack of 16 ounce Equate-brand sanitizer for $50.