#1. Look at the Zestimate. Now you know the wrong answer.
#2. Evaluate the subject property regarding tangible assets.
#3. Collect community sales of last 90 days. (if more that 5 in the past 30 days, use those)
#4. Identify like kind
#5. Reconcile value of tangible assets included depreciation.
#6. Compare this number to step #1. When you have had a good laugh, continue.
#7. Apply 'big bank' skew to identify potential obstacles
#8. Evaluate alternatives to this home.
#9. Now you have value, price, appraisal and options. Create a proposal that acheives your buying/selling objectives.
#10. Suddenly realize YOU DO NOT HAVE ACCESS to the reliable information you need.
You will find it beneficial to rely on those who have successfully helped others in the purchase and sale of dozens of homes every year. Only those who are immersed in the business know who to apply the numbers, understand the dynamics, identify the obstacle, provide the solution, guide you around the traps, keep you from harm and present the options designed to benefit you most.
Best of success.