Until a colleague, who was until recently a student, got wind of the whole thing. He offered me to collect some bottles, all I had to do was come by his house to collect them.
Turns out he misheard me. I have a 30 liter bucket, but there's only 15 liters of beer in there. He had gotten enough bottles for 30 liters!
I took 'em all home, and I spent yesterday evening peeling off the labels and rinsing out the cigarette butts and washing the bottles in the washing machine. I have more than enough to bottle up my beer!
And now I get the advice to lager after all -- so my lead time has increased by two weeks. Oh well.