Build-a-Box Bundles: Run a Builder Page

A build-a-box bundle gives the shopper a page with steps, a few choices at each one, and a box price that is only known when the last pick is made. That is the opposite of a fixed set, where you decided everything in advance, and it moves the risk from your product editor to your price rule. This post covers when a builder page is worth the extra setup, how to design the steps, how to choose between a fixed box price and a percentage off the picks, why the box that hurts you most can be a different one from the most expensive box, and how to keep stock honest when every component sells out on its own schedule. The numbers come from one invented catalog that you can replace with your own.

When a builder page beats a fixed bundle

A fixed bundle is right when you know which products belong together. A builder page is right when the shopper's preference is the product: a gift box for someone whose tastes the buyer knows better than you, a variety box where nobody wants the same four things, or a first box for a subscription where choosing makes the shopper feel invested. It is the wrong tool when you have six products and one sensible combination. For a pick-any set at a flat price with no steps, mix and match bundles on Shopify covers the pricing of the worst basket; this post starts where the choices are grouped into steps and the number of possible boxes grows quickly.

What Shopify's own Bundles app does and does not do

Shopify's Help Center says that to create bundles you need a bundles app installed. For fixed and multipack bundles it points to the free Shopify Bundles app, and it states that the app "doesn't support mix-and-match bundles." For a custom offering, it says a store on Shopify Plus can build one with the Bundles APIs. The eligibility page also describes how bundles draw down stock: the product with the lowest inventory level determines how many bundles can be sold. Neither page we read describes a multi-step builder page or a way to build one without an app or custom work, so we do not claim that Shopify offers one.

Freebies Engine by Log Studio Lab has a Bundle builder page template, described as "A page where shoppers build a box step by step." Plan requirements for bundle templates are on the pricing page; do not assume they match the requirements of any other tool.

Designing the steps

Every step is a decision the shopper must finish, so each one should earn its place. Four rules keep a builder page short:

• One category per step. A base item, then the extras, then an add-on. A step that mixes categories asks the shopper to compare things that cannot be compared.
• Say the count, not the range. "Choose 2" is easier to finish than "choose 1 to 4". Use a minimum below the maximum only when the box price rises with the number of picks.
• Three to five options per step. With two options there is no builder, and with twelve there is no decision. Hold the long tail for a different page.
• Show the running price. The shopper sees the price at every step, so the final number is never a surprise.

Two price rules, tested on every box

The example catalog has three steps. Step 1 asks for one item from a mug, a candle or a soap set. Step 2 asks for two of a tea tin, a honey jar, a chocolate bar or a cookie box. Step 3 asks for one of a tote or a notebook. That gives 3 × 6 × 2 = 36 possible boxes. Retail prices and landed costs are invented:

Across the 36 boxes, the retail value runs from 56 to 84 dollars and the landed cost from 27 to 43 dollars. Now price the box two ways.

A fixed box price. Charge 70 dollars whatever the picks. The box with the highest cost, a mug, honey, a cookie box and a tote, costs 43 dollars and earns 27 dollars, a margin of 38.6 percent. That looks safe, but the cheapest-to-buy box, a soap set, tea, chocolate and a notebook, has a retail value of only 56 dollars. The shopper would pay 14 dollars more than the same items sell for separately. A fixed price needs a catalog where retail values stay close together, or the shopper who builds a modest box feels cheated.

A percentage off the sum of the picks. The shopper pays the retail total minus a set percentage, so the discount is the same on every box and the price always looks fair. The risk moves: the box with the lowest margin is no longer the one that costs most.

Under a percentage rule the worst box is the one whose cost is the largest share of its retail value. The cookie box has the highest cost-to-price ratio in the catalog, 10 of 18 dollars, and the rest of that box sits at half, so the box retails for 68 dollars and costs 35, a ratio of 51.5 percent. The costliest box has a ratio of 51.2 percent. The gap is narrow in this catalog and wider where your items have uneven cost ratios, but the lesson holds: the worst box under a percentage rule is not found by looking for the costliest box. Enumerate every combination, which a spreadsheet does in a few lines, and compare the lowest margin with the floor you can accept. If your floor is 35 percent, 20 percent off passes and 25 percent off fails. Discount floors so a promo never loses money shows how to set that number.

Shipping, payment fees and packaging change with the box, and these margins leave them out. A heavier box costs more to ship, so test the weight of the worst box too.

Stock: components sell out separately

On a Shopify bundle, the Help Center says the product with the lowest inventory level determines how many bundles can be sold. On a builder page the effect is different, because a shopper who finds a chosen item gone abandons the step, not the page. Plan the stock from the picks, not the boxes. Assume you expect 120 boxes during a campaign and each box takes 2 picks from step 2 across 4 options. That is 240 picks, 60 per option if they split evenly. They will not. If the most popular option could take 40 percent of the picks, stock it for 96, and treat a number like that as your reorder floor. Then decide the rule for an option that sells out: hide it, or swap in a stand-in of equal cost so the box price rule still holds. Do not leave a sold-out option clickable.

Building the page

Set the steps and the picks from the table above, choose the price rule that passes your floor on the worst box, and write the box price rule into the page in one sentence. The holiday version of this decision, with a set that cannot be assembled from single items, is in holiday gift set bundles, and bundle pricing strategy covers the general question of how deep a bundle discount can go. The Boston page applies the same step-by-step builder to a dorm box. Before launch, buy one box that includes the highest-cost and lowest-margin picks and confirm the price, the stock and the order lines match.