Just for the check, if I'm understanding it correctly;
Iota-transactions are free. Now I like to send my Iota's from Bitfinex to Binance. I can do that without any costs?
No, I guess that's too good to be true... I guess Bitfinex will charge me for a (minimal) amount? How high will this amount be, Bitfinex will charge me?
Allready, thanks for the answers.

finex will charge you 0.5Miota for any withdraw
Correct me if I am wrong but the free of charge transactions should be valid if only wallet to wallet. I doubt any exchange will allow free transactions at all, this is how exchanges make money basically, from fees

Recently I noticed that Bitfinex also imposed fees for deposits if below 1000 USD...
yep you are right, but normally the make money with trading fees and not with transaction fees.
one month ago it was free to deposit and withdraw iota on finex.
guess the amount of new user spaming their engine results in that kind of fees. also new user registration is suspended.