WARNING:
This trade route is only a guideline and is based on my personal trading experience. I cannot guarantee a profit for you, since the prices and are subject to change. So don't blame me if you lose some money. But it's pretty reliable for me so far :)
Please check market rates before you buy anything. If the rate is above 130%, it is usually risky.
South Italy + South France
(Naples <---> Syracuse) + (Genova <--> Marseille)
(VENICE BAY, see Venice Bay post)
Ragusa ---> Naples* --> Syracuse --> Naples* --> Calvi (SOUTH FRANCE)
buy: wheat* sell: olive sell: glasswork sell: olive (see below)
olive buy: glasswork lavender fish
lavender buy: olive buy: lemon oil
fish cermatic
wheat* lavender
bronze sculpture
Calvi --> Pisa --> Genova* --> Marseille* -->
buy: cheese sell: cheese sell: pickle sell: woolen fabric
lavender cermatic knitted fabric
bronze sculp. buy: knitted fabric marble sculp.
buy: pickle woolen fabric buy: salt
marble sculp. antique art wine
bronze sculp.
Calvi --> Pisa --> Genova* --> Naples (SOUTH ITALY)
buy: cheese sell: cheese sell: pickle
buy: pickle bronze sculp.
crossbow wine
salt
buy: knitted fabric
woolen fabric
* = cities with guilds
*wheat = wheat can be processed into FLOUR, which can be sold at spot
Note: cheap food like egg can be CONVERTED to food to save some money