This is a good idea. Except that most of what I'm seeing are mouse feet and screws and batteries for wireless keyboards. It's something but there are plenty of other parts that could use replacing. I have a G305 mouse and they have the feet and screws but they are $15 each which is pretty crazy pricing. Maybe for a pack of 3 or something but just for one it's stupid. I specifically picked this mouse because it uses standard mouse switches for the left/right/middle buttons. Many mice use a smaller switch for the middle/wheel switch making finding replacements harder. I replaced them all with Kailh silent switches which makes using my mouse much more quiet without constant clicking noises.
And the better option then to have one off parts available for specific models, they could design their products to reuse the same parts as much as possible so that there would be more uses which could help keep prices lower.