Buy the Delta: How to Turn Your MTG Collection Into an Upgrade Plan

2026-04-11 | 4 min read

Buy the Delta: How to Turn Your MTG Collection Into an Upgrade Plan

Most Commander upgrade sessions are messy.

You open three deck tabs, search for staples, forget what you already own, price the same card twice, and finally end up with a checkout that feels random instead of intentional.

That is exactly why we shipped the Buy-the-Delta Planner.

Instead of asking "what cards are good?", the planner asks a better question:

What is the cheapest useful gap between the deck you want and the cards you already have?

What the planner actually does

The planner works in three modes:

  1. Commander mode - start from a commander and generate a color-legal shortlist built from staples plus theme hits.
  2. Precon mode - start from an imported stock Commander precon or a curated precon package and compare it against your local collection.
  3. Deck-list mode - paste a list and turn it into a missing-cards basket with quantity-aware pricing.

For each mode, the planner:

  • checks the collection saved in this browser
  • marks cards as owned or missing
  • estimates the known missing spend
  • sorts the missing pile by the cheapest path first
  • gives you a single TCGplayer shopping CTA for the remaining stack

That means less tab juggling and fewer duplicate buys.

Why "buy the delta" matters

If you already own 30-60% of a deck shell, you should not shop like you are starting from zero.

The useful number is not "how much does this deck cost?"

The useful number is:

How much am I actually missing right now?

That shift matters for:

  • precon upgrades
  • slowly assembled Commander decks
  • binder-to-battlefield brewing
  • budgeting around reprints and price swings

It also creates a better affiliate flow because the click happens after the missing stack is already filtered down to cards you still need.

Best ways to use it

1. Start from a commander

If you know the commander but do not want to paste a full list yet, Commander mode is the fastest way to get a shortlist.

Example workflow:

  1. Open the planner
  2. Enter a commander
  3. Save the resulting shortlist locally
  4. Check the missing spend
  5. Shop only the uncovered cards

This is especially good when you want a sane first pass before tuning the last 20-30 flex slots.

2. Use it with precons

Precons are where this tool feels the cleanest.

You can now do this two ways:

  1. pick an imported stock Commander precon directly inside the planner and load the real deck list without pasting anything
  2. open a guide like Quick Draw upgrades under $25, review the curated package, then jump into the planner with that curated precon context already selected

That turns "I should probably upgrade this" into:

  • here are the best first pickups
  • here is what I already own
  • here is the missing spend
  • here is the basket to shop

The important part is that stock precons and curated upgrade guides now live side by side. If the imported Commander catalog has the deck, the planner can use the exact stock list. If you are following a site-specific upgrade guide, the planner can still work from the curated package or your own pasted shortlist.

3. Paste a real deck list

If you already have a list from Moxfield, Archidekt, notes, or Discord, paste it into deck-list mode.

The parser keeps simple quantity lines like:

1 Sol Ring
1 Arcane Signet
2x Counterspell

That is the quickest path from "here is the deck I want" to "here is what I still need to buy."

Saved plans and price-drop alerts

The planner is local-first on purpose.

When you save a plan, the app stores that upgrade basket in your browser and checks later snapshots against the same plan. If the total comes down, you get an on-site price-drop alert the next time you load it.

That gives you a simple retention loop without needing accounts first:

  1. save the plan
  2. come back later
  3. see whether the basket is cheaper
  4. decide whether now is the buy window

Share pages are built in

You can also create public share pages for upgrade plans.

That is useful when you want to send a list to:

  • a playgroup
  • a Discord server
  • a partner who is splitting an order
  • your future self on another device

We also now support public collection share pages, so the collection and planner can both participate in the same loop.

Good pairings with the rest of the site

The best stack right now looks like this:

  1. Scan cards at a table or from a trade binder
  2. save those into your local collection
  3. browse Commander Staples for common pickups
  4. run the Buy-the-Delta Planner
  5. click the missing-only shopping CTA

That is the workflow we want: discovery -> compare -> save -> shop.

The practical goal

This planner is not trying to replace deep deck tuning.

It is trying to solve the highest-friction part of buying cards:

figuring out what you still need and what it will cost.

If that sounds like your bottleneck, start here:

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