You really need to know the market before you do BPO. That is even more important for most areas now that market corrections have or are taking place.
Don't try to make BPO's a profit center just to float a new real estate career, its a bad choice as it can significantly take away from your primary goals of listing properties. Have you discussed this with your broker? Will the broker support the activity? Does his E&O cover you for BPO's. Do you have your on E&O?