I did hire a lawyer and our application was approved. The lawyer, himself, gave me very good advice which was key to the ultimate success of our application. For this, I paid extra, as I requested more than one phone consultation. But it was well worth it. This was information that the firm's paralegals either didn't know or didn't concern themselves with. Most of the "processing" and review of my application documents was done by paralegals and I found more than one error in their emails to me. But like I said, the eventual outcome was positive.
If I had known then what I know now, I could have applied without their help. And if I were to give you advice, I would say this: Pay for a consultation with a lawyer who will seriously think about your specific qualifications, situation, etc. and give you specific advice.
Personally, I found the phone consultations with the lawyer much more cost-beneficial than having paralegals look over my documents. The paralegals never said one word about my application documents - except that they had received them.