I've completed the large quick sell pack like 6 times and it would only give me around 1k - 7500 coins at most, I feel screwed over cuz it costs me a lot of coins for completing it!
The odds of getting a large amount in a large quick sell pack is small. Sounds funny, right? Can't get a large amount in a large quick sell. Sadly, that's the reality. Of all the large quick sells I've redeemed I'd say 95% of them are 1,000 or 5,000 coins.
Most of the time you can sell the six silver and four gold trophies in the auction house for way more coins than you will get out of a quick sell.