Hi,
I have a question. I’m using Exclusive Account with Envato, my account is from Thailand. I set the price $16+ Buyer fee $4 per song. Every time that I sold it I will got only $10 per song because of author fee for sale.
So I would like to know is it normally?
And last 2 months ago I sale music in broadcast & film, my price is $305 [$241+buyer fee $64] and I’ve got $160.62. Is it normally?
CocoBasic is right.
Price is $20 -> minus $4 fee = $16
$6 is exactly 37,5% of $16
so your fees are $4 (buyer fee) and $6 (37,5% fee) -> and you have your $10 left for you. 
Check this tabels CocoBasic showed you - after your sales brake $3 750 then your fee will be 36,25%… and so on untill you get 12,50% fee after you brake $75 000 in sales.
Also keep in mind there are USA taxes which are taken automatically when US person buy something from you -> it could be 5% or 10% or even 30% depending on Thailand treaty with USA so you shoud check this too and check if you filled up W8 form for non us residents.
;]