I don't know what others do, but I buy my favorite espresso beans weekly, and then every few weeks I buy a bag of something new that I haven't tried before. That way I know I'm going to have really good espresso almost all the time but with the occasional addition of something new for a variety.
I usually buy 12 ounce bags. If you only buy 100 grams, then if it takes a few shots to dial in the grind you won't have much left to enjoy for a few days.
I enjoyed the La Marzocco Home espresso subscription for a few months last year. It was a good way for me to try new and different beans, but the timing of the shipments didn't always fit my schedule so I discontinued it.