Greetings Justin:
University of Illinois Extension Forestry does not conduct appraisals of standing timber, trees, or logs over the internet due to the simple reason that standing timber, trees, and logs must be field-graded on-site for quality, or grade. Timber or log quality is the principal factor in determining net value.
Therefore, please contact your local Iowa DNR district forester for on-site technical assistance regarding the value, sale, and marketing of your trees.
IA DNR Forestry Assistance: http://www.iowadnr.gov/Environment/Forestry/ForestryLandownerAssistance/DistrictForesterContacts.aspx