Shopify 100%
Your time is way more valuable then the $30 month + 2.5% transactions fees so you can be free to research for products, niches, content or novelties. It gives you room to fail and start a new shop in no time. You now have the chance to try it for free in 90 days. You can set up a Pro Shopify store in 1 day , and duplicate into 5-10 stores in 2 days for different niches. Trial and error niches + fb marketing PPE tests till you have the 3 best ones on the next 7 days so you can invest the most on SEO, marketing, research. You dont have to worry with payments going wrong, bugs and etc. Trust me, shopify will change your life and i truly believe this is the model of the future.
Beautiful websites are way overated in 2020. Check
https://www.piperloucollection.com/ they make like 15 million $ per year and the website is ugly as fu** IMO.
Speed Performance, Time Saving for research, Good Products, Brand/Content Consistency, Smart Marketing and Customer Service its basically all you should be worried about. Everything else counts 5% tops.