Can I charge extra for optional items on top of a fixed-price bundle?
No — Zenbox Bundle Builder does not currently support charging additional amounts for optional items when Fixed Pricing is enabled.
Understanding Fixed Pricing
When Fixed Pricing is enabled in a bundle:
The total price of the bundle is locked and set by the merchant (using the “Start Price” field).
All products selected during the bundle process — including optional steps — are included in that fixed price.
The price at checkout will not change, regardless of how many items are selected across steps.
In-app (Enable fixed pricing):
Fixed pricing in bundle:
Why optional add-ons do not increase the price
Even if a step is marked as optional and contains extra products, any selected items in that step are still treated as part of the overall bundle and are included in the fixed price total. The app does not currently support dynamic pricing on top of a fixed base when Fixed Pricing is turned on.
How discounts work with Fixed Pricing
Zenbox does offer flexible discount settings under Fixed Pricing:
You can apply a discount to the entire bundle
Or apply a discount to a specific step only (for example, Step 2 only gets 20% off, the rest remains at full price)
However, these discounts only affect how the fixed bundle price is calculated, and they do not allow additional pricing on top of the fixed amount.
Workaround: Use Dynamic Pricing Instead
If you want to upsell optional products and have them added on top of the base bundle price, you’ll need to:
Disable Fixed Pricing
Use the Start Price as a base amount (optional)
Add steps and products as needed
Optional items will be priced based on their individual product prices, and the final total will reflect the sum of all selections
Still have questions?
If you’re unsure which setup is best for your store, feel free to reach out to our support team. We’re happy to review your bundle and help you configure it based on your pricing goals.