Hiring an ad agency can get expensive, but more likely than not, you can find an agency that fits what your business needs that's also within your price range. 

Depending on the agency and their different packages, you can expect to  pay $400 to $25,000 a month; however, for a local business looking to advertise, a more realistic range would be something between $400-$8,000 depending on several factors:

• The size of your business
• The type and amount of services an agency provides
• The quality, size, and experience of the advertising agency

When comparing advertising agencies, it's important to understand the type of advertising agency and its services. 

For example, hiring a full-service advertising agency is comparable to adding a complete marketing division to your business, so it will usually cost more than a traditional marketing agency, an agency that focuses only on traditional forms of media, or a digital marketing agency that would focus on various online avenues. 

You can also check out a previous article that breaks down the different types of advertising agencies and cost in more detail:

https://www.savvysme.com.au/article/9419-The-Average-Advertising-Agency-Costs-in-Australia-SavvySME