Mystery-Box Collectibles App Build

I’m creating a real-money mystery-box experience for physical collectibles: users purchase a sealed “vault,” a weighted random draw reveals the exact item they’ve won, and they then choose to Keep it, Sell it back at 85 percent of its value, or Ship it home... (Budget: $3000 - $5000 USD, Jobs: Android, API Development, Backend Development, iOS Development, iPad, iPhone, Mobile App Development, Payment Processing)