$925 for shipping? Does this seem right?

Hi, I am starting my FBA business and created a product from scratch. I’m worried my manufacturer is overcharging me for shipping. I was quoted $920 to Whittier CA Which is near the long beach port (my house). I was also quoted $925 to ship directly to the Amazon warehouse in Illinois which would require LTL to travel much further.

I have 42 master cartons of 504 items total. Master cartons are 48x35x49 cm, or 19x14x19 Inches. Each master carton weighs 18lbs and is not palletized.

Does this seem reasonable?? Any advice would help thank you.