Yes, in almost all cases, premium WordPress themes are a worthwhile investment, unless you're willing to settle for low resolution images and the limited functionality. While there are some free themes that are ideal for certain projects, a premium theme is a miniscule investment, usually under $60 at <a href="https://themeforest.net/">ThemeForest</a>, for an individual who is starting an online business.
When something is free, a large number of people will take advantage of it, therefore, your WordPress websites built with a free theme are indistinguishable from other sites with the same theme. With a premium theme, you can build your brand image and differentiate your business from your competitors.
Having support, which you only receive with premium themes, is absolutely worth the cost. Theme creators will fix bugs and develop security patches as needed, however, with free themes, you are on your own.
Premium themes are available for eCommerce, creating social networks and more. It's possible, with a great deal of time and skill to build a store with a free theme, nevertheless, a premium allows you to have your site up and running in minutes, with everything working correctly. When it comes to WordPress themes, you get what you pay for.