I don't understand where the appraisers came up with their number.
The price has a lot to do with the actual land value. Lots between Metairie Road and the railroad tracks are the most valuable probably ranging from between $200K to $400K depending on which street.
Lots on the other side of the railroad tracks near the playground are a little cheaper probably in the $150K to $250K range; same thing goes for the lots on the north side of Metairie Road.
So if you get a good estimate on what the lot by itself is worth, then the price per square foot begins to make a little more sense depending on how new/old the house really is.
Old Metairie is a very interesting area to appraise because one street could have tons of huge homes and nice oak trees etc and then the next street over could have a lots of small, old cottages.