Condition is KING. No matter what one collects, if you collect based on condition then you will never lose money. The mint stuff always holds value even in a recession.
SC62 if you're just starting out and can afford it. You may want to consider having fewer pieces but higher quality. Quality over quantity in the long run yields a greater return. As exemplified by the two Sunoco signs sold.
Dave's Garage & Memorabilia, Inc.