Do we need to budget for a tracking-app plan upgrade (e.g., to a server-side tier) at the same time we migrate to Checkout Extensibility?

Which tracking setups force a new spend after the checkout upgrade?

Only tracking that ran in the Additional scripts box in Checkout settings, or in an app's script tag, forces a new spend. The new Thank you and Order status pages take tracking only as pixels, so each of those tags needs a pixel before it reports again. Shopify says "The Thank you page supports app pixels for tracking and analytics", from an app or a custom pixel (Shopify Help Center, October 2026). When each Shopify plan lost its script tags sets the date your store crossed.

Can a free route replace the old tag?

Yes for two common pasted tags, a Meta tag and a Google Tag Manager container, because Shopify gives each a home with no subscription.

• A Meta tag. At the Enhanced or Maximum data-sharing level in the Facebook & Instagram app, "The Conversions API sends the purchase event between Shopify and Facebook servers" (Shopify Help Center, October 2026). The Conversions API is Meta's server-side application programming interface (API). The app is free to install, and its listing adds "Additional charges may apply" (Meta, October 2026).
• A Google Tag Manager container. Shopify's custom pixel guides include "Create a Google Tag Manager custom pixel" (Shopify Help Center, October 2026). A custom pixel is added in the pixels manager of the Shopify admin rather than bought as an app (Shopify Help Center, October 2026). But "Adding and using custom pixels is unsupported by Shopify", so its upkeep is yours.

So a paid tier is a choice about accuracy and destinations, not a cost the migration forces. Which Conversions API to set up first covers Google and TikTok.

How much should you budget when you do need a paid tier?

Budget $225 a month for Elevar, the server-side tracking app Audiense now sells, and $650 once purchases go to a third destination or an affiliate network. Destinations set the tier before orders do: Elevar's Core plan sends to only 2 ad or analytics destinations (Audiense, October 2026). Core covers 2,000 orders a month and charges $0.50 for each extra order (Elevar listing, October 2026). Advanced covers 10,000 orders and up to 4 destinations, affiliate networks included. So a store sending purchases to Meta, Google and an affiliate network starts on Advanced, whatever its order count.

For a three-year line, Deploi's checkout tracking record puts an Elevar-class app, setup and audit included, at an illustrative $11,800 to $30,200 (Deploi decision record, October 2026). That is the record's estimate for a rented app, not a quote. Elevar's full plan ladder, Premium and Elite included, has its own answer.

How do you sequence the spend so you only buy once?

Sequence the spend with the inventory first and the tool last, so you pay only for pixels that nothing free covers.

1. List every tag that predates the upgrade. Below Plus, Shopify's upgrade guide "categorizes your additional scripts based on their purpose, such as authentication or order tracking", and flags apps that haven't been updated (Shopify Help Center, October 2026).
2. Turn on Meta's server-side sharing at Enhanced or Maximum in the Facebook & Instagram app.
3. List the channels still fed from a tag, and check whether each vendor ships an app pixel, and on which plan.
4. Then price the tool, with destination caps in hand. Buying first is how a team pays Elevar's $650 a month (Elevar listing, October 2026) to replace one tag a free app pixel covers.
5. Re-check two weeks after the switch. New pixels require Marketing and Analytics permissions by default (Shopify Help Center, October 2026), so markets that require consent report fewer events.

When should the tracking upgrade stay out of the migration budget?

Keep the tracking upgrade out of the migration budget when the migration doesn't change what you can measure.