Thank You very much for it.
I guess making bigger transaction over higher quantity of smaller ones will be an option then to avoid fees and being more secured. But then I have another question - fee sometimes differs why is that ?
Fee is based on amount of data you are sending, not the amount of BTC you are sending. Basically it is the difference between the inputs and the outputs in your transaction.
For example if you receive many dust transactions and collect over time large sum of BTC, when you try to send it, you will pay humongous fee just because number of the outputs of your transaction is so high.
Well, if you want to know more please read this short article:
https://blog.blockchain.com/2016/12/15/bitcoin-transaction-fees-what-are-they-why-should-you-care/