This math is out of touch with how good static websites are actually made these days, imho.
1. $100 per hour min for anyone good. Possibly more if in a high-cost labor market and/or working with certain agencies (mostly boutique). So that’s 130 hours right there.
2. No discussion of interaction with customer. That could be many, many hours depending on the customer and project specs.
3. The 130 hours for design and coding are way, way over actual time required unless the specs are highly stylized. My guess for each would be 4-20 hours, depending on complexity.
4. Depending on the site, copywriting and SEO might be a bigger labor/money sink than the design and coding.
All that said, there are many agencies who can make good, basic static websites for $5-7k plus hosting. The catch is knowing which ones are good.
Another possible issue, depending on the agency, is what is the smallest account that they will do business with. $13k may have been the agency’s minimum.