If your "low-level job" is already 50: what I generally did was run beast tribes and solo hunts while queued for roulettes. I'd usually be done in the overworld right around the time the last roulette popped.
Generally 2-3 levels per day, in 2-3 hours.
With the added bonus that you could do these on different classes. So if you hate tanking, healing, melee, casters ... whatever in actual content - you can level them with the beast tribe and hunts, while doing roulette with a different class.