Such a loaded question! Pricing is determined by many, many factors. The cost of doing business in Sand Diego and Washington are much, much different. You have a small space, so more than likely, time and labor will be a factor, not a "square foot" price. Also, the cost of products in any epoxy system can differ greatly as well. The amount of preparation of your concrete will effect your cost as well.
Is there a coating to be removed? Is there cracks that need to be isolated? Does the concrete need to be self leveled? Are there any moisture issues? Lastly, the amount of material or application method to create the floor that will meet your expectations.
Maybe I over analyze a bit, but it's impossible and unfair to you to throw you a square foot price without knowing all these factors.
Calling some reputable seamless flooring contractors in your area, seeing there work first hand and making an informed decision would be the correct way to go.