Maryland is taking a look at its real estate holdings and is thinking about selling some of its parcels. Earlier this year, the state hired Addison, Texas, real estate advisors Staubach Co. to catalog its assets and make suggestions on what to do with them. All together, the state owns almost 500,000 acres, valued at just under $8 billion. About $3 billion of that is land; the rest includes more than 5,200 buildings and improvements.