Major Life Decision

I am on the doorstep of employment and rather then being excited I am scared to death. I have studied for and passed the state insurance health accident and sickness exam and have a meeting in a couple hours to become a agent for a major company. The problem is the job has no benefits, no employment designation, no salary (100% commission based) and would force to give up my existing income sources, my primary insurance and force me to hire a full time PCA which is no small task. It also an industry (sales cold calling based) that has a high upside but a low success rate and high level of turnover. I would be given no more then three months to prove myself and could wind up out on my ass with no sources of income having paid a ton of out of pocket up front cost. Can a beggar be a chooser? Does someone who's have held down full time employment at the advanced age of 28 really turn down an opportunity? I have two hours to make up my mind and I have no idea what am going to do? I hope I make the right choice!