Stacy, I have to be the contrarian here. I really like that you are trying to prevent committing the number TWO mistake made in a real esate transaction. Please take some time to read the other 24 top mistakes made in a real estate transaction. (source HTGV top 25 real esate mistakes.)
Depending upon where you live in Michigan, this may not be the time to sell your home. Will you be purchasing a larger or more expensive home? Will you be moving to an area where home values are rapidly increasing? Are you in danger of loosing your home to foreclosure? If the answer to these questions is No, then I would really think hard about selling in this market.
If the answer is yes to any of these questions, then David is absolutely correct. Pay the 300 to 500 dollars and get a "not for refinance" appraisal for your home. I know this is not what you want to hear, but it is what you need to hear in this market.
Any of the agents from Michigan below would gladly give you an honest opinion of the value of your home. Unfortunately, I doubt that you would pay attention to their advice.