The jute sole doesn't fail where you'd expect, at the toe or the heel. It goes at the arch, a slow crumbling that starts around week six if you've worn them properly, and by the end of a summer there's a soft gap you can feel through your sock on gravel. Cheap ones go there in a fortnight. Good ones take all season to get there, which is really the only difference that matters.
If you own none, start with a flat, closed toe pair in a plain canvas, navy or a stone colour rather than anything printed. The flat version tells you quickly whether the shape suits your foot before you commit to a wedge, and a closed toe means you can wear them on a longer walk without the strap cutting between your toes by lunchtime. Wedges are lovely but they're a second pair decision, once you know the brand's last fits you.
These are a May to September shoe and not much else. They're right for a long lunch outside, a market, an afternoon where you're on your feet on pavement rather than grass, because grass and anything damp turns the sole to a sponge almost instantly. I'd avoid them for a festival or a day you know will involve a field. Mine survived one soggy picnic and never looked the same.
Sizing on espadrilles runs generous because the canvas and the rope both give a bit with wear, so if you're between sizes, go down rather than up. The real fit problem isn't length, it's width at the ball of the foot. Too narrow and the canvas won't stretch enough to stop them rubbing, too wide and your foot slides forward on the sole with every step, which wrecks the heel of the shoe fast. Try them on standing up, not sitting, and walk a proper distance in the shop rather than three steps to the mirror.
Before you buy, check where the stitching meets the sole at the back of the heel, that's the seam that goes first on a bad pair and it should feel firm, not like it's only tacked on. Press the sole itself between your fingers. A good one has some structure and resistance, a cheap one feels like stiff cardboard that will snap its shape within weeks. Check the rope edge isn't already fraying loose threads in the box, because that's not a sign of character, that's a sign of what's coming by August.