You might get some help from the resources listed here:
http://info.ex.ac.uk/~RDavies/arian/current/howmuch.html
>Date: Thu, 6 Feb 2003 10:36:52 -0500
>From: Sketcher <[log in to unmask]>
>Subject: Florin value
>
>To Historians All!
>
>My question : How can "fifteen florins" be converted to a 2003 monetary
>value?
>
>Leo Dodd
>Historic Brighton