If you're not planning on spending much, your best bet is these Pull&Bear Espadrilles. It's a fantastic piece, while not very costly. Another strong contender for your wardrobe is these Anna Field Espadrilles. While the price of this item is rather reasonable, it will definitely attract a lot of attention. You might also want to consider these Kanna Espadrilles. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you're looking for something in between pricewise, we've got your back with these Castaner Espadrilles. This item is bound to become a total wardrobe staple.
If you're not the one to skimp on clothes, then what you're looking for is these Tod's Espadrilles. It's more expensive but worth your money.