What is a Antonius Stradivarius Cremonensis Faciebat Anno 1734 made in japan really worth?

A real one is worth in the millions. However, the chance of finding a previously unknown Strad is astronomical whereas coming across a modern copy, worth less than $2000, is extremely common, just check out Ebay. Except for a few stolen Strads only 500 or so originals remain and their locations are known.