This is a nice way to look at it. Phrased differently, come up with a personal brand, buy what you need to make it happen, and stick to it. If it doesn't last more than a year, the brand was bad. Take the hit, re-brand, buy new fonts.

On the other hand, designers need to buy many different fonts since each client needs a unique brand – unless you're one of those designers that impresses your own brand on your clients.