Replacing a Jamb liner - Sun Windows 

Good to know what those pads are for, thanks. But my problem is with the vinyl jamb liner prices - so far priced more than I pay for the complete, brand new, Pella double hungs. The essential springs and miscellaneous stuff are very cheap, (reasonable), it’s the vinyl channels that cost. Being a carpenter thinking of making the channels out of wood - for the seven windows (!) The original liners, now breaking apart were for Brosco wood frame, double glazed, double hungs. {Is anything easy?}