I have a bag I sell in 3 sizes. I want to create a bundle where if the customer buys 1 of each variant they get a discount.
How is it possible to do this so it tracks with the inventory? I have tried bundle builder, revy bundles......none of which allow the variant bundle. I don't want to pay for the app as I am a startup and it is already costing me more than i wanted for my shop (after massive issues connecting with facebook which is why I joined shopify to begin with!).
Check out the discount options you can set within Shopify: https://help.shopify.com/en/manual/discounts/automatic-discounts
If you need prebuilt bundles that track inventory then it may be a different scenario as you need an app to manage these products and then could apply discounts to these prebuilt bundles.
We have a developed a new app that lets you create pre built bundles as well as have variants where each one is also a bundle. When an order comes in we split the bundle into individual components in the Shopify order. This solves the inventory issue as its one of the main reasons we have built it. You could create bundles and set discounts accordingly but depends on the options you want to have as there is a limit of 100 variants so can't get too complicated.
In the end it comes down to how you want to configure it and what is more important - inventory tracking or discounts. Have a think about it and if you would like to discuss further can email me at firstname.lastname@example.org and can brainstorm so ideas.
I am also trying to build a new bundle app. So I've done some research in this field. If you want to offer this discount without extra apps, you can manually create a pseudo product with these 3 variants. Set the price with your discount and compare at price with the total variant prices. After that, make a simple banner. Add this banner to the product page linking to the pseudo product.
A drawback is the inventory cannot be tracked for the individual products.
Another way is to make a custom page to include this offer on your own. Create an alternate template based on the collection. Add an add bundle to cart button. When the user clicks this button, use cart ajax to add all products to cart and apply a discount. But you have to play with liquid or you can hire someone to handle the dirty work for you.