Photographer Demanding $1500

I have a small business in the US making wooden home goods, which I sell in boutiques locally. To highlight a new launch, I reposted three pictures of a shopping center that’s home to the shop where I launched my new product (i.e., “we launch today in X store, come and check it out!). My repost was of 3 photos that a local photographer had taken of the shopping center. I credited the photographer in my repost.

The photographer contacted me today and is demanding $500 for each of the three photos for perpetual usage rights, saying I infringed on their copyright. I sincerely apologized and took the post down, but they’re still demanding payment. I’m a small business owner - what are my options here?