A Magic: The Gathering player created a SMS price checker for card prices using Twilio and .NET Core, allowing users to send a text message with the name of a card to receive its current prices in USD, Euros, and Tix. The application queries the Scryfall API, which provides pricing information without requiring authentication, but with rate limits. The application uses TwiML to generate an SMS response with the card's prices. After building the application locally, it was deployed using ngrok and configured to respond to incoming texts from a Twilio phone number.