In Barcelona, the most expensive sneaker store is undoubtedly Space Sneakers. They sell Spartan Green Dunks for €500, which is €100 more than at least five other stores within a 500-meter radius that offer the same shoes for 20-25% less. The staff at Space Sneakers, particularly one employee, was quite arrogant and disrespectful, insisting that their shoes are authentic and they are aware of their sources. I would not recommend this store, as you can find the same sneakers at a significantly lower price nearby.