Options that add to price

-- url of the page with the problem -- : initiativeready.com
-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.4.3
-- Error-message(debug-mod must be tuned on) -- : N/A

I am selling services that may or may not need travel and expenses billed. I am thinking about fix-pricing the travel to the four timezone regions of the US. For argument sake, let's say I want to have the pacific timezone add $800 to the order, Mountain $1,100, central $1,500, etc. I want it to:
1) Be required based on the category.
2) only once per order.
This is a lot like shipping... but it is me that is being shipped.
How would you suggest I do this?
As I understand:
Options are applied by line item (an not required)
Variants replace the price.
Products are note required.
So I don't either will work.

Thank you, Nicolas.

I will try that. I am not sure how the user experience will be, but it should work.

The other option that I did not think about earlier was was combining options and variants. I think this will work. Step are:

1. Create an option product
2. add variants for each timezone
3. Add the option to the service product
4. This will add that cost to the product

The user could add two of these changes on the order, but that should be rare.

I do my best at keeping Hikashop (and Joomla) as out-of-box as I can--even at the cost of functionality. Makes upgrades, debugging and these note easier.