Well I don't know whether that land would have been developable if sold on the open market. However I just sold my property in Medford, so this might offer a little insight. My house needed a lot of work, so my realtor did a little research to determine whether we should market the property as a "tear down" or actually sell the house. I had 3.2 acres, all woods right up to the house. We decided it was worth about $250,000 just for the land so we gave up on the tear-down idea as the house added value to the deal (I sold for about $300,000 in the end).
However, using the number above:
$250,000/3.2 = $78,125 per acre
And 158 acres x $78,125 = $12,343,750.
But of course that assumes you could develop the land. Even so, it seems like $2.4M isn't excessive. You couldn't even buy two "McMansions" for that price in Medford today