Ok, neither GG nor I have won the lottery so you will have to pay.
You should decide now who is giving their spare tickets for Frankfurt to Shannon and Mike.
Here a short list:
Shannon: 2 tickets from Silvia (Hannover) and whoever shouts first (Frankfurt)
Mike: 2 tickets from Silvia (Hannover) and whoever shouts first (Frankfurt)
Mia: Two tickets from Silvia (Hannover) and Leif (Frankfurt)
Galeongirl: One ticket from Leif (Frankfurt)
Leif: One ticket from Galeongirl (Hannover), but her postage is higher.
Marjolein: Two tickets from Galeongirl (Hannover) and Leif (Frankfurt)
Postage international: €15.90
Price per ticket: €70
Cost for Shannon and Mike: 4 x 70 + 15.9 = 295.9
Cost for Mia: 2 x 70 + 3.98 = 143.98
I paid one for GG, GG paid one for me, so you will get 3.98 from me.
Cost for Marjolein: 2 x 70 + 3.98 = 143.98 (You could pay GG directly)
Hope I forgot no one and if anyone doesn't understand what I did here please shout.
I will send the bill via PayPal. I now included the non-rounded prices. Subject to change due to exchange rates.