It has been a long time since I've used any baluns.

What is the lowest priced 4:1 balun on the market?

Hi, Your best bet would be to look at the archives of this group concerning
baluns. A low priced, high performance, one that will work over a wide dynamic
range, is very difficult. If you could narrow your design constraints, the
Wireman, and Byte Mark sell some that might work.
This is an Amateur newsgroup, sounds like you are trying to make some money,
if I am wrong, sorry.
73 Gary N4AST