Chatres Cathedral - cost to rebuild most of the cathedral in the early twelfth centuryabout 50 million dollars in 1972 money. Or around 260 million dollars in 2010 money.
There's another estimate here though, that is in terms of annual yearly wages for the labour.Santiago cathedral used a workforce of 50 skilled labourers from 1075 to 1211. So, that's around 6850 labourer years. The average US wage for a stone mason is around 40,000 dollars, so that works out to around 274 million dollars. Converting back to 2010 dollars, that's around 250 million dollars. That's just the labour, you also have to pay for materials. They estimated an equal cost for the materials. So that's around a half a billion dollars.
Kheops-Pyramid Great pyramid of Giza, 878 million dollars if built with today's materials and modern labour, build 170 of those.
Stonehenge (credit Diego Delsa) - eleven million dollars worth of labour, could build 13,600 using neolithic methods