There were times when I farmed airdrops, I have a piece of advice for you, don't limit yourself to just airdrop hunts.
Always research new networks and join them, I can't say anything about fees if you want to farm airdrops, you will need to burn some tokens.
There were times when I earned from airdrops, and times when I didn't.
You get an airdrop, it makes up for all your losses and brings more, the airdrop business is a job that requires a bit of luck, and regular follow-up as well as luck.