Hi,
it would be great if you can make a mockup.
I usually make some changes for the customers. If I have to repeat some section, I can make it without cost because it is fast and easy.
But, if I have to create new section with new options, it has its price. I have to create new code and test it. That should lead time to develop. The price for a customization in a wordpress theme is $10.
Regards