Are Pierco 1 - piece frames the way to go?
 
As I threw out my 1996 catalogs, I can't confirm the prices, but as I recall,
a new wood medium frame with plastic foundation was more expensive than a new
all-plastic medium frame (I only use mediums).   Add to that your assembly
time for the wood frame and potential for wax moth damage, and I contend the
all-plastic frame wins the cost analysis hands down.
 
W. G. Miller
Gaithersburg, MD