Small springs are very useful parts. I've always had trouble sourcing them. It seems that unless I am buying hundreds of the same type, there aren't many places that will sell one or two small springs in an assortment of types and sizes.
Recently, before taking a computer printer to the local recycling depot, I spent a pleasant hour or so taking it apart and salvaging the springs it contained. I was able to retreive several dozen in a delightful assortment of sizes and types.
This one was a Canon printer, I forget which model, but all printers contain an interesting and potentially useful variety of springs, both compression and expansion types. They are not at all difficult to remove, particularly if you are about to scrap the printer, you don't care about damaging it.
I keep my small spring stock in four small bins divided as compression or expansion and small and large making it a bit easier for me to find just the right spring for the next project.
Plus I am helping the recycle effort in a very small way by separating the printer into plastic, metal and electronic parts before I dispose of it.