You can set custom rates based on your product quantity as mentioned above with PH MultiCarrier Shipping Label. If you want to ship based on shipping zones, the app makes it possible. You can create shipping zones based on country, states & postcodes.
Sharing some screenshots for a better understanding:
I use the 3rd party fulfillment service company so could not use this app as we don’t use the accounts of those express courier companies.
Now the problem is our setting is 100pcs per item when selecting 200pcs or 300pcs or more then the shipping cost could not change to 200pcs or 300pcs etc… automatically.