Well, first of all, what is enough for you? I see you live in the UK, so I suppose $3,000 at least before taxes would be considered making a living, yes? For a small apartment, no car.
I also live in an expensive country with high taxes, and I would say $4,000 would be absolutely minimum for me to make a living. I would be considered among the lowest paid here with that income…
For a good car and a small house I would say $6,000 before taxes would be required. In some countries that would make you rich of course, but sadly not here…
I haven’t had a real job in 16 years, and I have actually never had a real full-time job. I have been able to make internet work pull in enough for me. And hopefully I never have to get a real job…
Anyway, I have never been able to make a living JUST from AudioJungle, not even back during the good years. I have always combined different websites and royalties. That is what you have to do as a small independent musician.
AudioJungle can be one piece of the puzzle (small piece today), but still a great way to get your music out there. If it resonates with people, it might become popular, and after a few years royalties can start coming in. Lots of them.
As with any artistic endeavor there are no guarantees, and there is no such thing as “expected” salary for the hours put in.
SHORT ANSWER:
$3,000 per month from JUST AudioJungle sales? Very unlikely. A few here do, but they are not many now (probably less than 10). But with AudioJungle as a little piece of the puzzle it is absolutely possible.
Some that used to make $20,000 per month now make around $2,000 or even less.
Some of them registered with a PRO and used YouTube royalty collection early, and are likely earning a lot from that now. Others only recently started registering their tracks, now that sales have gone down.
They will have a really tough time now since it will take years for those royalties to really start coming in. Decisions that likely cost them hundreds of thousands…