Hold tight, you still have a chance of getting an offer from melbourne.
But if that really falls through, if you're so keen to move out, why not consider student accommodation around monash, clayton? Like ballerina pointed out, accommodation is a LOT cheaper there than it is around uom. Even if you have to pass up on the job, the money you save on accommodation might not make it so bad. And you'll surely be able to find work in that area, even if it's not as fantastic as the job you've been offered. Any part time job at all should give you pretty secure hours, and most places will be really reasonable/understanding with other commitments when they assign you shifts. Out of curiosity, may I ask what the job you've currently been offered is?
Alternatively, if you're willing to travel, you can always still move into the city area (non student accommodation tends to be cheaper anyways), keep the job, and travel to Monash when you need to be in for pracs etc. Streaming lectures isn't that bad btw, I prefer to stream my lectures, even when I'm already at uni. XD;; Then just get a transfer into uom after sem1.