I don't think anyone is gonna buy a $25 Starbucks giftcard for... $20. Way too high of a price. I get $50 Starbucks egift cards for $10... Maybe change your price to like $8 to $10. Someone will buy it them.
-If you sold your cards locally, since you have physical cards, just put them on craigslist for like $17 to $20. You can get cash then