Lots of people take on second jobs to make ends meet. Finding a hole in the marketplace, one genius couple used their side hustle to pull in some big bucks.

Juston and Kristen Herbert earned $30,000 last year, simply reselling Trader Joe’s “Everything But The Bagel” seasoning on Amazon. The Los Angeles based duo would visit multiple locations around the area, buying up cases at a time of the $2 product, then flipping them for $6.75 each.

According to Delish, the Herberts would sell around 100 bottles a day, along with products from other retailers like Lowes, the 99 Cent Store, and Walmart.