Weed hadn't been that cheap since 1979.

And for putting it on sale at the rock-bottom price of $1 gram, a medical marijuana dispensary in Pennsylvania earned a sharp rebuke from the state Department of Health.

Justice Grown Pennsylvania operates dispensaries in the northeastern part of the state.

Last week, at its Edwardsville shop, right over the bridge from Wilkes-Barre, the chain celebrated its first sales of  marijuana "flower" by offering two strains at $1 a gram. They were the only store in the state to offer it at that price point.

Patients, who learned about the almost-too-good-to-be-true deal through Facebook, lined up early at a coal-country strip mall last Wednesday for their shot at super-cheap samples of Lemon Sweet Skunk and Cherry Diesel. Each patient was limited to two grams. Usually those strains, produced by the grower Terrapin Pennsylvania, sell for $10 to $15 a gram.

One problem: The state forbids promotions or discounts on cannabis. The state does allow dispensaries to offer "special rates" for veterans and seniors at the discretion of the shop owners.  But coupons and other marketing stunts are verboten.

"It's in the law," said Department of Health spokeswoman April Hutcheson. "The law prohibits discounts. You can't run a promotional sale on medical marijuana. We let them know that they were in violation."

Hutcheson said the department contacted Justice Grown the day before the sale, warning that it was "not an acceptable activity."

Yet 134 patients were able to scoop up bargain-basement priced "dry leaf" — the state's term for plant material —  before Justice Grown exhausted the inventory.

Was it legal?

"It was completely compliant," said Justice Grown Pennsylvania's CEO, Abbe Kruger. "It didn't even fit the definition of a discount because it had never been priced before. We just priced it that low."

That's one way to work around the law.

The store sold 268 grams of "popcorn bud," the smaller but no-less potent flowers of the cannabis strains, for a buck each.

"It was the first day we had flower," Kruger said. "Some dispensaries had parties, but this was our way of celebrating. I think it was our way of giving a gift to our patients."

Hutcheson said the Department of Health just wanted "to make sure they don't knowingly violate any parts of the regulations."

In other words, don't expect any more fire sales to happen again soon.

"We want to make sure they continue to provide medicines to patients but also comply with the law," Hutcheson said. "We realize this is a new business structure. There isn't a formula [for discipline]. We're working through it."