This is what I can find at my local Lowe's in their plumbing section. It's super cheap and VERY strong. The picks that I make are much stronger than my Sparrows picks, and probably even stronger than my SouthOrd and Peterson stuff.
Then again, it could be due to the material being about 0.0265" in thickness. It polishes very nicely too.
Also, I do not use cutting wheels for making my picks, I use grinding stones similar to these.
Ninja edit: I'm not sure if every metal is like this, but this stuff throws a lot of sparks. Don't forget eye protection.