my health insurance has a concept called called bridge amount which kicks in after $1500 of medical bills paid by it, the bridge amount is $750 for me + 1 dependent and l need to shell this out of my pocket after which again they take care, l donno if l should take a secondary insurance to take care of this, but that will almost cost the same. Any ideas ?

You are probably correct. The premium for the secondary policy will more likely than not exceed the benefit. Most policies do not just pick up a balance. Most often they only pay the balance up to what they would have paid if primary.