My answer is, it depends on the speed-time limit you want.

For the faster transaction, of course, you need to pay a high amount for that. And you can calculate your transaction cost here, https://bitcoinfees.net/ including the details of a speed limit when it will be confirmed.

Exactly, and using the GDAX platform your Bitcoin network transfers are free and fast. Here is the guide on that. Or I think most probably custodial wallet has a feature like this, but you can't have a free transaction when it comes to an external wallet.