Disclaimer: I haven't built anything yet.
Few people spend the money to get a well-researched and robust system from the beginning. I've been getting the impression that many people start off with something they can afford.
After they gain some experience and see the results, they often want higher volts, and greater generating/storing capacity. This often means that as a system is upgraded, the older smaller components are sold at very good prices.
FWIW, I am planning on a separate component panel like Woof suggests.