I have also found the small, reclosable bags at flea markets but you have to
watch the quality.  Sometimes it seems these are intended for short term use
and the seal just won't open if it has been closed for a long period of
time.  However, they often have the really small bags for sale.  I now get
my bags from a local hobby store -- around here that means Hobby Lobby.  I
have heard you can also get the bags from coin dealers.

Tom Eichhorst in New Mexico, USA