You can't save them all. The only time you should take them is if Petsmart agreed to give them to you for free; you have the funds to care for them; and you have the experience and tools to know what to do. If you have to give them a dime for it, don't bother. Secondly, rescue work is more than adopting a pet. It almost always comes with an expense that the original owner may have known about but won't pay for it. If you decide to 'rescue' it anyway, you will need to use your own funds and you will need to know what you are doing beforehand. Some people may be generous enough to give you a few dollars here and there but gathering $600 for a snake with mites is a daunting task.