Man, I've gotta level with ya...
I've been in the hunt for a Flagg for about a year. There are certain parts that are going to fetch a substantial price on the open market, so I add the cost of shipping & average sale to any stripped down Flagg I am prospecting.
You have a hefty list. And a hefty price tag.
I would weigh this on item condition. If the structure is white and clean, no yellowing, and the stickers have not begun peeling, pieces are solid w/o cracks, than maybe. But even then, maybe not. Shipping to Greece should not exceed $130. Seller packaging & effort should not exceed $30. Really, you are looking at a stripped down Flagg for around $250, which is about right if the coloring is fine for you.
The issue you have here isn't really about the inventory of the Flagg, so much as it is directly finding a source willing to make the time & energy invested in shipping this across the pond.
I would sort your searches on Ebay for sellers that are willing to ship internationally, and do a 60 day search for Flagg's.
You might be surprised.
Stripped Flaggs go for $180-$240 often, depending on what items are missing. Wait for the one that is right for you, and bite.
This is a hefty investment. I feel you 100% man; have been right there at auction end and have had to let a few go because the missing piece count was too high.
Man, Hasbro needs to just do it and make a new one. Even with a $299 price tag, this thing would move boots.