I've been working as Frontend Developer for 2 months right now (I know that's not much).
I would recommend you to study some frameworks like Bootstrap(I hate it), JQUERY(It's not that hard), learn a few CSS pre-processors (I use Sass or Less it depends on the project) and Gulp & Webpack (Those are task-runners they are great).
About the second question... I don't know how the pricing works since I make full responsive websites that are identical to the design for my company.