(debtor was real estate "flipper" that entered into option contract that gave debtor right to buy property from another party; mortgage on property was facing foreclosure; parties also signed short sale agreement under which debtor was to use reasonable efforts to negotiate short sale with holder of mortgage from which debtor would profit, otherwise property would proceed to foreclosure; mortgage released for $130,000; post-petition, debtor entered into sales contract to sell property for $179,000; debtor then exercised option and bought property for $130,000 and then sold it and received $30,839.13 in cash at closing; trustee sought proceeds of sale and bankruptcy court granted trustee's motion for summary judgment on grounds that sales proceeds were property of debtor's bankruptcy estate; district court affirmed, and appellate court also affirmed).