A customized design requires some communication with the designer to identify what your needs are and what you want in terms of design, purchasing flow and other functionality features such as newsletter. It takes time and energy, but is necessary. In the end you’ll have a unique shop that fits your market and audience, and not the least present your product in a proper way. Existing online stores or customers who already have an online presence primarily choose this option.
An alternative to the customized online store is using a template. There are plenty of great examples that help keep down both the cost and development time. The downside is, of course, that you won’t get a unique solution and the fact that you might have to sacrifice some functionality or design that you otherwise would have liked to have.
The template solution is a good choice if you’re just getting started. Getting started with your sales and gaining some experience before you make a unique design might be a good idea in the long run.
You could also choose a template at first and then upgrade to a unique design. WordPress and WooCommerce will still work, so you wouldn’t have to get a completely new platform. The system is perfectly capable of handling design changes and possible new functionalities.