About your question:

Can you send sample of the fence rails and posts?
if you need samples. The samples is free, but you need bear the shipping cost USD55. Hope you understand please.

What is the harmonized code for importing and taxes?
Aluminum post: 7604210000
WPC Fence Panel: 39189090

What’s does shipping cost for the total amount 560 feet of  WPC Privacy Fence?
China Shandong Qingdao to Los Angeles Port
Shipping fee：85$ 1m3 85x9+30$(AMS) = 795$
Logistics costs: 295$
Restocking fee: 13.5$ 1m3 13.5x9+40 =161.5
destination port charges: After the goods arrive
Clearance fee:After the goods arrive