This is actually kind of a strange question.
What's so weird about it is that most small businesses (again, I focus on working with one- and two-person businesses) shouldn't be trying to compete with the big guys.
I recommend that small businesses niche their services and products, and focus on being good at a small subset of activities in their specialty, or niche the subset of customers who they work with – or both.
If you're well-defined and well-niched, then competing with the "big guys" shouldn't be so much of an issue.
Also, the amount that a small business needs to spend to stay competitive and to market their business annually depends on a lot of factors, like:
- How established the business is
- How big their customer list is
- How they choose to market (for example, writing articles and emailing them to your own newsletter list is less expensive than taking out a full page ad in a magazine)
- Their business goals for the year (the marketing spend for a business trying to gross $150,000 a year will probably be different than the spend for a business trying to gross $1.5 million)
- What exactly the business is, and how the industry as a whole tends to market
This is just a small fraction of the factors that influence marketing and branding costs.
But, the more clear you can be on your business's brand personality, service and product offerings, competitive situation and differentiators, and target audience, the less you can usually spend trying to market (because, if you define these 4 factors well, then your marketing and branding should be more effective overall!)