The writer, whose real name is George Mentz, also sells certifications that you've likely never heard of.

Customers looking to sell books can always bring them to the main Magus store on Tuesdays, Fridays and Saturdays from 10 a.m. to 4 p.m. Magus Books offers either cash or 50% more in store credit.

Magus Books and Herbs will be celebrating its 20-year anniversary this September. Joseph Amara, executive vice president of Magus, said the store is popular with a unique crowd whose loyalty has kept ...