“Pick any 3 and save” is one of the highest-converting offers in ecommerce — it gives shoppers control and a clear reason to add more. This guide shows how to set up a mix & match bundle on Shopify (also called build-a-box or BYOB): the shopper chooses any N products from a set, and the discount is enforced at checkout.
Fixed bundle vs mix & match
A fixed bundle is the same products every time — a starter kit. A mix & match bundle lets the shopper build their own from a curated pool — “choose any 3 candles,” “build your own 6-pack.” Mix & match wins whenever variety is the point: candles, coffee, snacks, cosmetics, supplements.
Two ways to build it
Option 1 — Shopify’s native Bundles app
Shopify’s free Shopify Bundles app can create a mix-and-match bundle as its own product: you add a pool of options and set how many the shopper picks. It tracks component inventory, so you won’t oversell. Its limit is merchandising — it’s a separate product page, not an offer that appears on your existing pages, and it can’t combine with quantity breaks, BOGO or a gift.
Option 2 — a product-page build-a-box widget
For a build-a-box that lives on the product page and discounts at the cart level, use an offer app. Our free Profit Flow AOV Bundle does this:
- Create a Mix & Match offer and choose the collection (the set) shoppers pick from.
- Set the threshold — how many they must pick (e.g. any 3) — and the discount (percentage or a fixed amount off each).
- The widget shows the set with checkboxes and a live “2 / 3 selected” counter; the Add button unlocks once the shopper hits the threshold.
- Publish, build a box, and go to checkout to confirm the discount holds.
Keep it checkout-safe
The reason cheap build-a-box widgets get gamed is that they discount in storefront JavaScript — a shopper can remove an item after the price drops and keep the discount. Enforce the offer with a Shopify Function instead: it counts how many items from the set are in the cart and applies the discount only when the threshold is met, re-checked server-side at checkout.
So if a shopper picks 3, gets the discount, then removes one on the cart page, the Function re-evaluates at checkout and the price reverts — no lost margin, no manual policing.
Good mix & match categories
- Candles / fragrance — pick any 3 scents.
- Coffee & tea — build your own 6-bag box.
- Snacks / supplements — choose any 4 flavours.
- Cosmetics — build a 5-piece routine from the range.
Combine it with quantity breaks, a free gift, or a per-unit variant selector for a full product-page offer — every mechanic enforced at checkout.
Profit Flow AOV Bundle runs mix & match build-a-box offers (and quantity breaks, BOGO, bundles and gifts) on any Online Store 2.0 theme, free. Add it to your store →