I'd try a
- hobby shop because they use thrust bearings.
-bicycle shop because in the rear sprokets on older bikes especially there are tiny bearings I sometime had to reassemble. Ask mechanic if he has an extra. My boss would order extras and I always had them in a tray on my workbench.
-Dollar store.
-hardware store.
-maybe you have a old computer fan that has ball bearing inside.
-check your household items that might contain a bearing hmm lighter, some fancy pens, cheap keychain but it is not really a ball bearing but might work as well eg:
