You spend a lot of money preparing for the social work licensing exam. How much of that spending is actually necessary? Hard to tell. People spend upwards of $800 on exam prep packages and don't pass. People spend next to nothing and ace the test. It's not about what you spend. It's about how ready you are when you go in to take the exam. You're studying to be a licensed social worker, not a stock broker. The amount you spend shouldn't exceed what you expect to make in a fairly short amount of time.
So what's essential to have to prep? You probably don't need one of the expensive study guides. The ASWB publishes for free on their website content outlines for each of the exams (clinical, masters, etc.). This lays out what you can expect to see on the test. All the pricey study guides do is fill in the some of the info--info you can easily fill in yourself for free with the help of the machine you're reading right now. The outline includes ethics? Read the NASW Code of Ethics. It's free on the net. The outline includes diagnosis. Well, you've probably got a DSM handy somewhere. Or can borrow one. You don't need to pay someone to summarize DSM diagnoses for you.
Also, what about all those textbooks from school? They should come in handy too.
You get the idea. Save the money for a massage. Maybe some practice tests. Take care of yourself. Be realistic about how challenging the exam is. It's passable. You don't have to baby yourself. And you don't have to go broke passing it. All good news, I hope!