The first Amiga, an A500, in the house, bought by my father, came from dutch retail-chain V&D.
The first I bought myself was a brandnew Amiga 3000. I got it through mail-order. If I remember correctly it was bought from CSV Riegert in Germany (they still exist but have no Amiga business). I had my parents sent Eurocheques to pay for the machine :-).
The other machines I ever owned were used ones fetched thru online sales or even fair-trades.