If there is a *real* art store anywhere near you 
(Michael's and Ben Franklin's don't really count) 
you can pick up the best of the best (Itoya 
archival quality) for under $15. Actually where I 
am the oversized ones (for cels with backgrounds) 
are like, $13.75 or something... and the small 
ones for regular sized cels without backgrounds 
was only $8.