BNIB
Brand new in box
Example
Planet Arlia Vegeta Funko Pop, BNIB. $2,000, fixed price

Related Slang
MIB | Mint in box |
NIB | New in box |
NRFB | Never removed from box |
OOTB | Out of the box |
Fresh | Brand new |
NIP | New in package |
OBO | Or best offer |
BIN | Buy it now |
Online sellers use the acronym BNIB to mean "brand new in box." This indicates the item they're selling has never been opened or used.
You're most likely to encounter this acronym on eBay, Craigslist, Facebook Marketplace, and other auction and sale websites. It's often used in listings for electronics and collectibles, to indicate these somewhat-expensive items are untouched and in great condition.