The final Ethereum transaction fee required to set up a Gnosis Safe depends on a number of parameters:
Number of owners.
Usage of the ProxyFactory.
Additional logic set (e.g. FallbackHandler).
The following numbers assume that you create a Gnosis Safe via our web interface at https://gnosis-safe.io/app/:
A Gnosis Safe with 2 owners requires about 263k gas.
A Gnosis Safe with 3 owners requires about 309k gas.
A Gnosis Safe with 4 owners requires about 331k gas.
The following calculates the transaction fee with a number of example gas prices:
An interactive calculator by @germartinez can be found here. Another one by @cryptoneur_eth is located here.