It seems like they've done all of this at a surprisingly low cost.
1 million assembly hours at 370 million project cost = 370 Euros/hour (assembly + management overhead costs).
1 million assembly hours at 370 million project cost = 370 Euros/hour (assembly + management overhead costs).
This means it generates way less neutron radiation, which in turn means less need for shielding and easier working conditions on and close to the machinery, avoids material degradation, ...
Also, if I understand German sources correctly the 370 million doesn't include wages of the people working there (maybe external construction contractors, but not the effort by MPI personnel). (EDIT: found a quote of ~1 billion EUR as cost for the entire project since 1995)