“I might need it someday”
The perceived need to hold onto something for someday is used by many people to avoid making a final decision about an object. If I can say I am keeping because I intend to use it, then I can justify having it.
The question I ask my clients is: “When did you use it last?” Often they say that it was a long time ago. If you haven’t used it in the past, what is the chance you will use it in the future? Let the item go. If you really need it in the future, you can get another one.
Jars and jars of random nuts, bolts, screws and nails seem to be the favorite “I might need it” item for men. When I ask how often they have actually found what they needed, most guys tell me it’s easier to run to the hardware store than dump out all the jars and search for something. Chances are you’ll need more than one screw anyway and waste a lot of time trying to find a match.
Buy what you need, then keep the leftovers organized so you can find them. Labeled zipper bags will hold most sizes of hardware and can be stored in a shoe box. Don’t keep the parts you didn’t use when you installed something.
Once the blinds are hung you probably won’t be moving them, so don’t keep the hardware for the other option. By the time you might need it you’ll be buying new blinds anyway.