thanks for the post
If you're not a developer go for Shopify. Even if you can afford to hire a developer you need someone with good experience to knowledge to get a smooth experience with Prestashop. That being said, it's much more flexible and open than Shopify but it will require a lot of investment in modules (that can be hit or miss btw) to get something awesome. Not to mention a lot of custom development on top of those modules to make it your own.
Overall it really depends on your budget and experience. None is truly free. If I'm honest, I think that Prestashop is more expensive to develop and maintain overall.
EDIT:
I forgot to mention that with Prestashop you can test a lot of modules by downloading them from this site and decide which is worth buying. Otherwise you can spend a lot of money of rubbish modules.
I personally don't have much experience with woocommerce but, from what knowledge I have, I would only use it for something simple like a restaurant menu or a bike shop where not a lot of products need to exist at once.Why not WooCommerce ?
Maybe as developer would be more lightweight than prestashop and more cheaper than shopify