CardStack

Every card you're selling — or hunting — in one stack. CardStack sits quietly in your browser and watches your own TCGplayer seller page, so your inventory, market prices, and profit stay current without a spreadsheet. Flip to the Buying side and it'll flag the moment a card you're hunting hits your price. WHAT IT TRACKS Selling side (Free & Pro): every listing you add gets its age, its real TCGplayer market price checked against that exact product, and a running price-history sparkline so you can see a card cooling off before you reprice it. Buying side (Free & Pro): search TCGplayer's catalog by name, pick the exact printing, set a Condition/Language you're targeting, and the price you're willing to pay. CardStack checks it against live market price, alerts you when it's worth pulling the trigger, and separately alerts you the moment a sold-out card gets new listings again. Flag sellers to avoid or prefer and CardStack flags their listings right on TCGplayer's own product pages, next to a banner showing how the current lowest price stacks up against your target. Pro also adds hourly price checks (Free checks every few hours), one-click links straight to a watched card's TCGplayer page, fee-aware profit (set your cost basis once and CardStack backs out TCGplayer's actual fee rate to show real net profit, not just revenue), bulk CSV import/export, and no cap on listings or watched cards. HOW IT GETS ITS DATA No account to connect, nothing to authorize. CardStack reads the TCGplayer Seller Portal page already open in your own browser tab. Market prices come from TCGplayer's own public per-product price page — the same number any visitor sees. CardStack never logs in on your behalf, never has your password, and never clicks, edits, or posts a listing for you. Everything it reads lives in your browser's own local storage; nothing is uploaded to a server CardStack runs. PLANS Free — $0. Up to 5 tracked listings and 15 watched cards, live TCGplayer market pricing, price + restock alerts, Condition/Language targeting, seller allow/avoid list, price-history sparkline, CSV export. Pro — $3.99/mo or $35/yr (annual works out to about $13 cheaper than paying monthly). Unlimited listings and watchlist, hourly price checks, one-click TCGplayer links, fee-aware cost & net profit tracking, bulk CSV import/export, everything in Free. WHY CARDSTACK, NOT ANOTHER TCGPLAYER TOOL Most TCGplayer extensions pick one side of the desk. TCGSniper and TCGPriceAlert are buy-side alert tools with no selling features at all; MTGStocks Companion tracks a collection but doesn't touch your seller listings and only covers one game. CardStack is the only one of the group that watches your own listings AND a buy watchlist from the same extension — so a reseller who both sources and sells cards doesn't need two tools running at once. The free tier is also built to be worth keeping, not a trial. Restock alerts, Condition/Language targeting, a seller allow/avoid list, and an on-page price-comparison banner are all free here — on the closest competitors, some of that is a paid-tier feature and some isn't offered at all. Where TCGPriceAlert's free plan caps out at 20 alerts (email/Telegram only) and TCGSniper's at 15, CardStack's free watchlist holds 15 cards plus a 5-listing selling tracker, with every feature above included, not held back for Pro. Pro is priced to be the cheapest paid tier in the category: $3.99/mo or $35/yr, against TCGSniper's $5/mo, TCGPriceAlert's $5.99–$11.99/mo, and MTGStocks' $4.25–$12.71/mo. It's also the only paid tier here that includes fee-aware net profit tracking — competitors' selling-side tools are either absent or separate standalone fee calculators, never built into the same extension that's already watching your listings. Every game on TCGplayer, not just one. CardStack reads whatever's rendered on the page, so it works identically no matter which game's marketplace you're buying or selling in — unlike single-game trackers that only cover one corner of TCGplayer. WHO IT'S FOR Resellers who both source and sell — sourcing underpriced cards on the Buying side while keeping their own storefront priced correctly on the Selling side, without switching tools. Sellers who want listing prices and profit margins to stay current without manually rechecking each one. Buyers who don't want to babysit a product page waiting for a restock or a price drop. If you only use one side of it, CardStack still works fine — you just won't touch the other half.