I've always replaced my windscreen wiper 'blades' before they become a problem... it's a safety thing with me. Of course, I'd remove them at the Auto-parts shop and take them in to ensure that I got the correct sizes as the passenger-side wiper is shorter than the other. I'd buy the best ones.
A few months ago, it was time to replace and I did my usual routine of walking the blades up to the counter of my local town's only auto-parts shop. For the first time in my experience, the proprietor didn't go to the rack of blades... instead he proceeded to remove the blade from the wiper mechanism then measured, cut and replaced just the 'rubber' wiper blade on both of the holders. I was gobsmacked. All these 'years' of tossing the whole, expensive, thing when the 'rubber' blade was readily replaceable and at a fraction of the cost.