Justin Bieber Celebrates With Hailey After He Sells Music Catalog For $200M

Justin Bieber's feeling himself after selling the rights to his entire library of music for $200 million ... and the proof is in the pants.

The Biebs busted out some eye-catching polka dot trousers Tuesday night as he headed out to dinner with wife, Hailey in New York City ... fresh off his huge payday.

Justin also rocked a pink jacket, beanie and a pair of black and brown boots ...  while Hailey wore a leather jacket and matching vest and heels.

The couple's got $200 million reasons to enjoy a night out in the Big Apple ... earlier in the day, Justin officially sold the rights to his publishing and artist royalties from his song catalog to Hipgnosis Songs Capital.

As we reported ... the deal's been in the works since December and it's being hailed as the most lucrative music rights sale for any artist from Justin's generation.

The $200 million pact reportedly covers all 290+ songs in Justin's library released through 2021 ... including his latest album, "Justice."

Something tells us Justin's picking up the tab tonight.