Hi Em,
80 Euros is to my very surprise an excellent rate through Deutsche Post!
The shipment is insured and you´ll get it fairly quickly.
Just for the record: Some shipping agencies like Wiesel offer containers which content is only dispatched after being full to a certain degree (Sammelcontainer). You´d be charged by cubic meter disregarding the actual weight and compared to UPS etc. it is next to nothing. The downside: you´d have to wait for the container to fill up and since it travels on a ship, it would take a while.
On minor reply to your assumption that you´d have to pay for your bike again and again one your several flight back home:
This would only be the case if you stayed overnight and had to check out your bike. Usually you can checck your luggage through how ever flights might be necessary. This shouldn´t cost you much, but it increases the chance of your bike being damaged drastically.
I personally feel that your made the right choice
Take care,
Björn