Ebay or Shopify, which one for my eshop?

You mentioned a good point, really appreciate.

Neither is better, it will just depend on what you want to accomplish. It will be easier to get setup on eBay tho. And you already have traffic there. But with shopify you have full control over the customer experience, which is what I would go with for a long term business.
And oh yeah there is an app that you can use on shopify that will import your eBay listings to your store. So you could use both

You aren't really avoiding the ongoing cost with wordpress. Yes you could could use something like woocommerce, but once you start seeing decent traffic then that $10 shared hosting isn't going to cut it. you will want to find a vps. you are looking at upwards of $50 there ongoing. On top of that if you are using shopify, you can use shopify payment gateway. If you are going with wordpress you will need one for an ecom store. yes you can checkout with regular old paypal, but not too professional, plus customers either have to have paypal or have to create one at time of checkout. But if you use paypal payments pro, then they can checkout as guests which is another $30 per month.So you're already at $80 per month there or more. and you don't have any supoort to help you with actually setting up your website. with shopify for $80 per month you have what you need and there are many other added benefits. like the ability to add coupon codes(just to name one great feature) And their support has helped me with any issues I've had setting up my site. In a lot of ways, shopify is the wordpress of ecommerce because there are so many apps (aka Plugins) that are made to use with shopify, you can virtually do everything with them without having to know any coding.