Etsy is lovely for little hand-crafted gems, I bought a gorgeous heart-shaped vase to hang on my wall. It is a little over-priced but for me, that's what comes from supporting other crafters who are paying higher fees and putting more care into their items than the mass-produced items on eBay and in stores, who are able to buy cheaper supplies and thus sell cheaper products.
If I'm looking for fabric I generally try and find the cheapest product. Sometimes it is etsy especially if I am buying from U.S because shipping always seems lower on etsy than ebay. Mostly however, supplies are cheaper from eBay and other large fabric stores.
Still, I would definitely encourage buying and selling on etsy as a way to support other crafters and maybe something you make will be the perfect item for somebody else. Also love the little personal touches like thank you notes (in fluent english) and better communication compared to ebay. I also think etsy is far better if you are looking for gifts because they are much more unique, have a better story and since it's mostly handmade, all you have to do is ask for a little customisation or gift wrapping.
Definitely try out etsy, I have had nothing but completely positive experiences that have more than made up for any overpricing and love knowing that I'm supporting somebody just like me and everybody else on this board who put a lot of love and care into our items.