As the others mentioned, marketing on a tight budget can be very challenging. But I have had success with tighter budgets than yours. Here's what I would consider.
1) Assuming a 40 hour week, you're budgeting $400/week, $1600/month. Rather than bring in a $10/hr level marketer, bring in a higher quality marketer for more pay and less hours. You would be amazed at what an experienced marketer can do in just a handful of hours.
2) Shift your expectations slightly from "strategy and implementing" to only "strategy". For a $50 Clarity call, you can get a strategist to get you started in the right direction. If you build a relationship with the strategist, you can check back in whenever you need the guidance.
3) Look at existing tools that you can leverage to help with implementation. Inbound marketing tools will help you establish a strong presence for relatively less effort. A Clarity expert can point out a few tools based on your requirements.
4) Lean on partner resources as much as you can. Sponsor content on their blogs. Contribute at their conferences. Leverage their existing channels and marketing resources to get your company out to a larger audience. This is one of the most cost effective steps you can take.
5) Find a way to open up more money for marketing in the future. You can have the best product or service in the world, but if no one knows about it, then what's the point?
I know you are looking to bring in a great marketing talent right now, but you might have to scratch and claw your way for a little while. I would strongly recommend getting on a call with a Clarity expert to discuss your requirements in more detail. They will save you a lot of time, money, and frustration in the long run.
If you would like to chat more, I'm here to help! Otherwise, give one of these fine experts who responded a chance.