LH2 - you may be right. However, are we talking about the basemap, or the Jeppesen database. The former costs "nothing" especially as Avmap is owned by CMAP who make the maps. The latter costs a lot more than nothing, but I don't think the OP is talking about that since this comes with any GPS database update anyway.
I was quoted Euro 400 (2 years ago?) for converting the basemap of a US unit to a European unit.
However I must admit that avmap.it was so poor at communication that getting answers was like pulling teeth. A shame as this is IMHO the best aviation GPS on the market.