Cost was the main reason due to daughter getting married. Second was time. Only wanted to spray the three coats of single stage compared to the many bc/cc. I had to do this in my garage and wasn't sure I could get it all done in one day. Third, I believe the single stage was just more convenient for me. Fourth, I wanted to use all SPI products and black was perfect.
I'm an amateur painter this being my fifth job. I really love the single stage. Give it a try. It really covered well also.