Thank your for contacting extension forestry at the University of Illinois. First, I do not appraise or value trees over the Internet or via telephone--especially for yard trees. Appraisals must be conducted in-person and on-site by someone you trust: a state agency forester, a professional consulting forester, a certified arborist, or a trusted wood worker / custom sawmill operator. They will be able to immediately assess the tree to determine whether removal of said tree would be a net “cost” endeavor or a net “profit” endeavor!
As I’ve mentioned time and time again throughout this forum, “tree value” is a function of many different variables: species; quality or grade (sawlog tree or veneer tree); merchantable log length; diameter (diameter at breast height or diameter at the small end of a log); volume; internal/external defects; demand; etc. Honestly, your yard tree could be worth in excess of $1000, or your tree could be worthless from a traditional lumber standpoint (i.e., it’s a firewood tree).
Valuing yard trees as potential sawlogs or veneer logs is even more complicated because of the liability and the physical cost of removing the tree from a yard-like environment. These removal costs are generally high because most yard trees are situated in tight, physical locations in proximity to houses, garages, utility lines, decks, driveways, patios, etc. Therefore, the physical cost of simply removing the tree tends to erode all potential net value the tree may have had as a sawlog. And in all honesty, the vast majority of yard tree removal projects end up becoming a net cost to the homeowner, not a net profit.
Again, I do not appraise trees over the phone or Internet, as there are simply too many variables to consider. However, a simple Web search for your state forestry agency will help you get the ball rolling!
Best of luck!