Hi,
1. You can buy the pack. We have a 30 days money back policy if you're not satisfied.
2. Yes, styles are NOT templates. What styles do is that they add a CSS file next to your template styling so that the elements of HikaShop get styled with a define set of colors/images/layouts. That way, if your template uses a black styling, you can have HikaShop elements fit that black styling by adding the black style available in the styles pack.
It doesn't mean that the style will replace the template styling.
However, for some pieces, we have commented out CSS code that you can uncomment in the style CSS in order to override what is normally done by the template. For example, we have CSS for buttons which is commented out in each style, because normally, it's your template which defines the style of the buttons.