Need to Buy Some F Stops Where Can I Buy Them

I have heard that F Stops are used a lot on some camera’s. Where can I find these F stops. Are they available at 7 Eleven, Boots, Target or other Shopping Markets and what kind of F stop should I buy when I find one.

For example, is it true that smaller number F stops are more expensive than big number ones? That seems weird. You would think they would cost more. There are so many decisions to make in fotagrefy.

Thanks for any advice… *F. Stop Fitzgerald…

*Tommy Estridge (first coined the name)