Multiverse General Store: From the Start, a Saintess Begs to Buy from Me?

I had just inherited a general store when the noble and immaculate Saintess of Light barged inside. Clutching her stomach, her pretty face pale and on the verge of tears, she cried, “Boss, quick, give me that miracle thing called a ‘period pad’! I’ll pay whatever it costs!”

Staring at the Seven Space pad in my hand, I fell into deep thought.

Later, dragons fought over spicy snack sticks, the Demon King offered up a magical tome for a sip of cola, and the Elven Queen traded the Spring of Life for a pack of instant noodles...

I just wanted to be a small-time shopkeeper. How did I become a big shot across all the worlds?