$400 for the set..
The Cosworth could go for more than $200 since its rare and Cosworth (the CA guys like them if they have a CARB sticker.) Just depends on how fast you want it to sell.
The Draxas isnt anything special but $150-200 shipped sounds fair, could go for less... A brand new OBX header sell brand new for just above $200 and is decently made.
If you arent in a rush, put them up in the for sale section here, set a price and use OBO if they dont sell right away.