Three sources, no app-switching
Each card detail page shows a price matrix with TCGPlayer (low / mid / market / high), CardMarket (low / avg / trend), and the eBay sold range. You do not need to bounce between three apps and a browser to triangulate fair value before listing or buying.
Currency conversion is built in. Prices display in your preferred currency (USD, EUR, GBP, CAD, AUD, JPY, and others) using the day's exchange rate, so the comparison is apples-to-apples even for buyers and sellers operating across borders.