Fashionable designer breeds are very expensive here, if someone offers you one for 500QR, there WILL be something wrong with it! You will probably get lots of offers from people who have bought them because they are cool puppies but have grown into aggressive untrained teenagers. Good luck.
The Veterinary Surgery 4367187 and Qaws 5396074 do have the abandoned designer dogs but are very careful about who they place them with. If people stipulate a pure breed/certain colour etc, it immediately makes us worried that people just want them because they look cute. You would also have to be prepared to take the dog when you leave. As the owner of a huge deerhound, I can assure you that big dogs are expensive to relocate. It cost me 12,000QR to bring my dog here.