they are on ebay regularly.  use search terms that will bring them up.
i got a nice stir plate with bars for $35 shipped.  it has no heat, and in
new condition but very slightly used a time or two.  it looks like a toy in
the pic, not like real lab gear.
real used lab plates with heat get $50-150, depending... vary all over the
place.
for just the bars, try pasting in and searching on:

mag* +stir* +(bar*,teflon,spinner*)

i just tried that and there's plenty.
  -----Original Message-----
  From: Linda [mailto:[email protected]]
  Sent: Sunday, November 11, 2007 9:52 AM
  To: [email protected]
  Subject: CS>Home made generator


        Thanks for the information on the measurements for silver.
        I would like to have a generator that makes the cs by itself but I
can't afford one.
        I have a great brother who knows how to do all that stuff though so
he is going to build the generating part for me.

        I know how to make a magnetic stirrer but I need a teflon coated
stir bar. These things were all over the place when I was working as a
laboratory tech; nobody ever gave them a thought, but since I retired I
found out just how expensive they are. Anyone know where I can get one at a
reasonable price? $90 for 12 is too much since I only need one. Didn't find
any on Ebay.

        Or maybe there is something else I can use for the stir bar......?

        Linda