Google: Convert 87,000 gold florins to US Dollars

I am used to being able to dump any conversion I need (measurements or currency) into Google with the syntax of "convert".n." ".unit." to ".desired format. In this case, I typed "Convert 87000 gold florins to US Dollars" as well as "Convert 87000 florins to US Dollars".  It ignored both and passed them to the search processor without attempting a conversion.

I was trying to determine the cost of the Tabernacle of the Virgin Marry in Florence, to aid in my understanding of some information from my Art History reading. Am I crazy for asking Google for this information?