밑져야 본전이다: have nothing to lose, here goes nothing, trying wouldn’t hurt

밑지다: to lose

본전: an original cost, principal

~ 해야 (해봤자) ~ 이다: even though ~, it’s still

Ex) 공부해봐야 소용없다: Even if you study, it’s no good.

→ Even if you do a losing business, you’ll still be left with the initial amount of money.

→ You won’t make any profits out of what you invested, but you’ll get what’s worth of how much you invested.

→ You have nothing to lose.