Your connects is money. It can cost you from $.15 to $.90. If a job mentions the client will hire between 3-5 freelancers, 2 have been hired, pay attention to the # of propoal submissions. Is it 20+? I would pass. Has the job been opened more than a few days? I'd probably pass on that as well.
Just because a client writes one thing they may do another. They may never hire (and a lot don't). You look for hire %, feedback, # of proposals submitted and hire # (if applicable).
Be smart about applying.