Packages
What are Packages?
Packages are a way of creating a bundle of products that can be sold as one product.
Install the CartThrob Package fieldtype
If you are installing a fresh install of CartThrob, you do not need to manually install the fieldtype, it will be done for you when you install the module. If you are upgrading from a previous version of CartThrob, you will need to install the fieldtype under Add-Ons > Fieldtypes before proceeding.
Add a new CartThrob Package field to your Products channel
Head to Admin > Channel Administration > Channel Fields to add a CartThrob Package field to your Products channel. You may, in fact, want to create a separate channel for Package products and map it accordingly in your CartThrob product settings.
Working with the CartThrob Package interface
When creating a new entry in your Packages channel, you will see the CartThrob Package Interface. Below the table which shows which products are part of the package, you will see a filter-able list of entries from your Product channel(s). Click on a product in the list to add it to the package. Once a product is in the package list, you can set defaults for Item Options/Price Modifiers, and set whether or not the user can change this selection.

CartThrob Packages Screenshot
How Prices Work
If your Packages channel has a price field mapped to it AND there is a value in the price field, that will be used as the package price. If you do not have a price field mapped OR you have left the price field blank, the price will be determined by the sum of all the products in the package.
Template Tags
Package within {exp:channel:entries}
{exp:channel:entries channel="product_packages"}
{if your_package_field_short_name}
<ul>
{your_package_field_short_name}
<li>{title} {entry_id} {url_title} etc.</li>
{/your_package_field_short_name}
</ul>
{/if}
{/exp:channel:entries}
Package within {exp:cartthrob:cart_items_info} & {exp:cartthrob:update_cart_form}
{exp:cartthrob:update_cart_form}
{exp:cartthrob:cart_items_info}
{title} {item_price} {quantity}<br />
{package}
{sub:title} - {sub:entry_id}<br />
{exp:cartthrob:item_options row_id="{sub:row_id}"}
{if allow_selection}
{select}
{/if}
{/exp:cartthrob:item_options}
{/package}
<input type="checkbox" value="1" name="delete[{row_id}]">
{/exp:cartthrob:cart_items_info}
<input type="submit" />
{/exp:cartthrob:update_cart_form}