Hi @asmeedhungana,
Adding logic to a contract to support Gas Station Network increases the size of the contract and hence the cost to deploy.
With regards running costs, someone needs to pay the gas for transactions. If that is the dapp developer, then this increases their costs.
The reason to do this is to minimize onboarding & UX friction for dapps.
Requiring users to use Ether to pay for transactions can be a huge hurdle and limit the number of users who even try your dapp.
There are two versions of the GSN:
- GSNv1 : Use in production now (though you may want to run your own relayer on mainnet to ensure availability).
- GSNv2 : In development at OpenGSN.org. See Doubling down on security for more details.
Assuming you are just getting started and depending on your development roadmap, you could look at the upcoming improvements in GSNv2. I suggest joining the OpenGSN telegram to get the latest news on GSNv2 development and timescales.