How to register an ENS domain with lower gas fees?

Hi guys, I'm new to the eth ecosystem. Unsurprisingly, gas has become an issue for me as $100 per swap or ens domain registration isn't all that reasonable to the average user. Still, I don't want to be left behind during a potential web3 revolution so want to register my ens domain. Does anyone know how that can be done cheaply, maybe on polygon? I still want it registered on eth if I ever to sell it on opensea (I think!). Any help would be massively appreciated.