Investors & landlords

The Realtor estimate can be done easily with the agent we bought the lots through. Once we have his estimate what do we do with it? 

When we get the reporting form from the title company to report it to the sale to the IRS we are worried it will look like we took a big loss for selling a $19,000 lot for $40,000, unless the TT software has a built solution? 

Thanks for your help.