I don't intend to discuss my career, you'll have to accept I know a thing about economics. Or not.

This -
"an equivalent financial estimate of value (to allow the route options to be reconsidered)" illustrates the problem with your assertion:

Of course heritage places can be expressed in financial terms but that DOESN'T indicate heritage value. And guess what? The short tunnel is being built because it's cheaper! That was worked out by scores of economists in the Treasury! So what does that tell you about Stonehenge's heritage value? Zilch! Sod all economists. And vote catching Tory politicians in the West of England!