MTG Commander ROI Analyzer

Analyze the return on investment of Magic: The Gathering Commander preconstructed decks by comparing current card market values against original MSRP. Built for collectors and resellers who want data-driven purchase decisions.

Features

• 98 Precon Decks - Complete coverage of Commander precons from 2022-2026
• Deck Comparison Table - Side-by-side comparison with sortable columns and filters
• Distributor ROI Calculations - Calculate ROI at wholesale pricing (40% discount default)
• BUY/HOLD/PASS Verdicts - Clear recommendations based on configurable ROI thresholds
• Card Search - Find specific cards across all decks
• Bulk Import - Import decklists from external sources
• Custom Deck Creation - Build and analyze your own deck configurations
• Deck Detail Pages - Individual deck breakdowns with card-by-card pricing
• Live Price Fallback - Automatic Scryfall API queries when static data is unavailable

Getting Started

Prerequisites

• Bun runtime

Installation

git clone <repository-url>
cd mtg-commander-roi
bun install

Development

bun dev

Open http://localhost:3000 in your browser.

Usage

1. Home Page - Select a deck from the dropdown to see instant ROI analysis with market value vs MSRP
2. Comparison Page - Browse all precons in a sortable table, filter by year/set, adjust distributor discount
3. Deck Detail Pages - Click any deck for card-by-card pricing breakdown and top value cards

Roadmap

Sprint 1 (Complete)

• Deck comparison table with sortable columns
• Distributor ROI calculations (40% discount default)
• BUY/HOLD/PASS verdict system
• ROI threshold filters
• Missing price handling (N/A display)
• Live Scryfall fallback when static data unavailable

Sprint 2 (Complete)

• TypeScript migration - Full conversion to .tsx with strict mode
• Comparison page enhancements - Year/set filters, sortable columns, batch refresh
• Loading state polish - Progress tracking, skeleton states

Sprint 3 (Complete)

• Mobile responsiveness - Responsive layouts across all pages
• Security hardening - Rate limiting, CSP headers, clickjacking protection
• Production tooling - ESLint, pre-commit hooks, Vercel Analytics
• Image optimization - Next.js Image component for Scryfall images

Backlog

• Historical ROI trends (requires database)
• TCGplayer/CardMarket purchase links
• Play Booster EV analysis

Routes

• / - Main ROI analyzer
• /compare - Deck comparison table
• /deck/[id] - Individual deck details
• /about - About page
• /contact - Contact form
• /privacy - Privacy policy
• /terms - Terms of service
• /blog - Blog index
• /blog/[slug] - Blog posts

Tech Stack

• Next.js 15 (App Router)
• React 19
• Tailwind CSS 4
• Bun

Scripts

Local CLI utilities for data management. Run with bun scripts/<script-name>.ts.

Price Updates

update-prices.ts - Fetches bulk card data from Scryfall and generates static pricing for all decks.

bun scripts/update-prices.ts

• Downloads Scryfall bulk data (~85K cards)
• Matches cards to deck set codes for accurate pricing
• Selects cheapest non-promo versions
• Outputs to public/data/prices.json
• Runs automatically via GitHub Actions (3x daily)

Lowest Listings Scraper

fetch-lowest-listings.ts - Scrapes TCGplayer for lowest listing prices on high-value cards.

# First-time setup
bun add playwright
bunx playwright install chromium

# Run scraper
bun scripts/fetch-lowest-listings.ts

# Options
bun scripts/fetch-lowest-listings.ts --limit 20          # Limit cards
bun scripts/fetch-lowest-listings.ts --skip-existing     # Skip already scraped
bun scripts/fetch-lowest-listings.ts --visible           # Show browser
bun scripts/fetch-lowest-listings.ts --min-price 20      # Set minimum price threshold
bun scripts/fetch-lowest-listings.ts --watchlist-only    # Only scrape watchlist cards
bun scripts/fetch-lowest-listings.ts --batch-pause 60    # Pause 60s every 50 cards

• Targets cards above minimum price (default $5) in positive-ROI decks
• Use --batch-pause for long runs to avoid rate limiting (pauses every 50 cards)
• Watchlist file (public/data/watchlist.json) prioritizes specific cards regardless of price
• Rate limited (1.5s between requests) to avoid blocks
• Outputs to public/data/lowest-listings.json
• Manual runs only (not automated)

Deck Import

import-decklist.ts - Imports deck lists from EDHREC precon pages.

bun scripts/import-decklist.ts

• Reads deck URLs from lib/precons.ts (edhrec field)
• Parses card lists and commander info
• Outputs to public/data/decklists.json

Trending Cards

fetch-trending.ts - Fetches trending commander cards from EDHREC.

bun scripts/fetch-trending.ts

• Scrapes daily/weekly trending commanders
• Outputs to public/data/trending.json

Maintenance Scripts

update-commander-flags.ts - Marks first card in each deck as commander.

bun scripts/update-commander-flags.ts

patch-prices-commanders.ts - Syncs commander flags from decklists to prices.json.

bun scripts/patch-prices-commanders.ts

Data Sources

Card data and prices provided by Scryfall. Prices update daily via GitHub Actions. All prices shown are for Near Mint (NM) condition.