Below is an example of what I need to design in the database:

There will be an option for a price, and then a special if it has one, and then I was wondering how I could do this if I wanted one of the options to be “FREE”.
See also there will be different currencies based on their country. Here is what I had in mind:
id - service_name - price - special_price - eco_friendly - free
1 - Rotate Tires - 9.00 - NULL - 1 - 1
2 - Service - 120.00- 100.00 - NULL - NULL
Would that work or is there a better way to do this? The eco-friendly will just display an icon in the HTML if it is set.
Thanks!
Set the special_price to 0 and let the presentation layer print FREE if the price is 0.
That way you can also do discount calculations and other things so that the price actually drops to 0 and then becomes “FREE” to the customer.