Niche Collector — Collection Tracker + Price Intelligence

"Niche Collector" is a portfolio tracking app designed for hobbyists who collect and value items like Hot Wheels, Gunpla, and mechanical keyboards. This app goes beyond traditional keyword search by storing purchase prices and current market values, enabling users to calculate gains or losses. The app automatically identifies and excludes fraudulent listings from the median value, ensuring honest portfolio tracking.

Key features include:

- Purchase price vs. current market comparison for each item

- Automatic market intelligence with price history from Tokopedia and Shopee

- Outlier detection to flag suspicious listings (e.g., a "scam Rp 5,000,000 listing")

- Structured data for math-based calculations (e.g., total market vs. total purchase costs)

- SEO optimization with open graph images, icons, sitemap, and web application metadata

The app utilizes structured content through Sanity.io, implementing custom schemas and enums that define various data types such as hobby categories, collectible items, collections, price histories, and wishlists. These schemas enable accurate calculations and data relationships, which are essential for proper analysis.

The app is built using the Sanity Framework, with its codebase available on GitHub (MIT license). The development process involved creating a custom Sanity app embedded within a Next.js application, resulting in a single deployment on Vercel. The project's unique features, such as vision debugging, GROQ queries, and custom math functions, demonstrate the app's technical prowess and suitability for niche hobbyist portfolios.