Things you don’t often see include “Closeout — Everything Must Go!” signs at bars:

The JRG Restaurant and Fashion Cafe — which is on Flatbush Avenue between Atlantic and Fifth avenues — is having a hedonistic last hurrah before it is torn down to make way for Ratner’s Atlantic Yards mega-development.

The bar, which is in the way of the Frank Gehry–designed arena, is liquidating its stock in a $30, all-you-can drink bacchanal.

And rest assured — that cash won’t buy you mere swill.

“It’s all premium liquor — we’re not talking house wine,” said the bar’s general manager Ray Rodriguez. Even better, the $30 gets you 15 percent off all food, which is a substance sometimes ingested during alcoholic binges.

. . .

The liquoricious deal will last only as long as the bar-cum-restaurant-cum-fashion house does — through the end of the month.

That’s because the premises are owned by Forest City Ratner, which has said it intends to start demolition for its 16-tower development as early as next month.

Location Scout: Atlantic Yards.