How can I get accurate international shipping rates from Australia in my listings?

[wildcherryclothing]

I have already sent a few items internationally and want to continue to do so.

Are any of the current international shipping options that come up in the listing templates accurate?

I have tried a couple but the rates my customers are charged are less than the current rate. For example my US customers are paying $21.10 for the 500g pre-paid bag while the current rate is $24. 

I am currently getting around this by listing this option (standard $24 to the US for under 500g items) only on my listings as most of my international customers are in the US. Other international customers need to contact me for rates. 

This is a temporary solution but I would love to just offer international tracked postage that accurately calculates by location according to current rates. 

It seems clear that this information needs to be updated in Ebay's database. I actually saw a discussion from 2016 with similar questions so I'm sure it's not just me! 

So any current better solutions? Also is this going to be updated?