If you want to avoid the entire bandwidth of the firehose, you need something like jetstream (at least until something like sharded relays come around).
However the relay gossip protocol is not as taxing as it used to be. Relay Sync 1.1 massively decreased overhead and it allows relays to run "thin", i.e. running with only a certain backlog of history and not carrying the full history of the network. So you can make a relay that only keeps 24 hours of history and it'll perpetually stay under like 100gb of storage (I don't remember the exact storage amount but storage size is pretty linear with backlog history).
If you want to avoid the entire bandwidth of the firehose, you need something like jetstream (at least until something like sharded relays come around).
However the relay gossip protocol is not as taxing as it used to be. Relay Sync 1.1 massively decreased overhead and it allows relays to run "thin", i.e. running with only a certain backlog of history and not carrying the full history of the network. So you can make a relay that only keeps 24 hours of history and it'll perpetually stay under like 100gb of storage (I don't remember the exact storage amount but storage size is pretty linear with backlog history).