I checked out the http://rusteprotection.com site you reccomended as we will be looking to add Swedish to our site soon. I loved how it looked on the site itself, it is very tidy and looks and functions seamlessly. But I noticed quickly that the other languages are on completely seperate shopify stores. This means if you have third party apps on your English or main store for example something like Foursixty which is pretty expensive at $100 a month, then you can times this by three just to have another two additional languages, you are basically going to pay whatever you are paying for your english site times how many other languages you want by installing them on domains/stores of their own. You also have to operate three seperate admin panels per language as they are literaly on three completely seperate stores. I just couldnt justify that to my clients or to myself... its crazy.
