Doorbuster

That SWAT team guy who gets to swing the battering ram when it comes time to bust down the traphouse door.

Also, it's a way to lure people into your retail store on Black Friday. At least, it was in the old days when hundreds of people would line up in front of stores at 3 am the day after Thanksgiving just to get a jump on Christmas shopping.

Sometimes known as a door crasher, the doorbuster is the super low-priced item that sells out quickly, but gets people thirsty for deals. Think: a 75" TV for $750. Except you only have 20 of them in stock, so people reach near-riot levels of aggressiveness to get them. Hence, a (hopefully figurative) desire to bust down the door.

Now that most shopping gets done online, there are fewer actual doors that get busted. It's more of an expression for low-priced, low-inventory items that drum up interest in a sale or event.