Prior to buying my FJR and Shipping it to Germany, I was shoping in Europe as well.
It seemed to me I got more bike for the dollar (exchange rates included) with purchasing the bike here even when you included my one way shipping.
I was just talking with the buddy that is going with me next year (renting).
when you consider rental rates, especially if your going for a multi week trip and even more so with trips in consecutive years I thought the purchase and ship made sense.
Green Card Insurance : varies depending on where you get it and how long your trip is
Storage: varies based on location
Knowing your bike vs a rental
doing 2-3 months I would buy and ship it, renting that's probably more than you could buy for and then just abandon it or sell it for parts to a shop