Quids in
Definition 1 of 1
Pro Tip 1/3UK Origin
Remember, 'quids in' is a phrase that originated in the UK, so it's best understood and most used there. 
After winning a bet, he exclaimed 'I'm quids in!'
Pro Tip 2/3Positive Outcome
'Quids in' refers to coming out ahead financially or gaining an advantage, often unexpectedly. 
The deal was so good, I was definitely quids in.
Pro Tip 3/3Casual Usage
Use 'quids in' in casual or informal settings; it's not typically used in formal contexts. 
At the pub with friends, you might hear 'Drinks are on me, I'm quids in tonight!'