For those following this thread in the future, here is a step by step run through of how I set this up:
Step 1 – Create YES/NO characteristics
In Hikashop > Products > Characteristics click on the "Add New" button
Name: Shoe hire
Add two values:
No
Yes
Click Save.
Step 2 – Create the option product
Open Hikashop > Products > Add a product
Name: Need to hire shoes?
(set tax and category as required, leave the price as zero)
In the
Characteristics area, click on the “Add” button
Find your characteristic called “Shoe hire”, select it then click OK. This will add the characteristic and return you to the product page.
Click “Apply” to save the product and keep you on the product page. Hikashop will build the list of variants applicable in the background.
Click on the “Manage variants” button (this will open the list of variants that Hikashop has built). Variant name will most likely be something like “Shoe hire_123” (for No) and “Shoe hire_124” (for Yes).
Click on the “No” variant to open it and set the Quantity to zero. If you don’t set this to zero the variant will be added to the cart as free. Keep the price as zero. Click Save.
Click on the “Yes” variant to open it and set the price to whatever you need. Click Save.[/ol]
Step 3 – Add the Option to the main product.
In
Hikashop > Products > Products open the product that you want to add the option to.
In the Options area, click on the “Add” button
Find the Shoe Hire product created above and select it, then hit OK.
Save the product and test in your front end.[/ol]
Once you get the hang of it, it's very easy!