.., as I learned today, seems to be understood as a two-part process by providers: one half is moving the number away from your old provider, the other is moving it to the new provider. While I've seen charges for moving a number to a provider, charging for moving it away came as shock for me today. And it's expensive like hell, holy sh..... cow. So I started looking around to see if this might be something separating good and evil providers but it doesn't look like that to me so far. Here is what I collected:

Provider/Contract	Charge in €
blau.de	24.95
callmobile.de / clever9	24.95
congstar	24.99
fonic	25.00
maxximal	30.72
simyo	25.00

Maybe I can find out why they all charge about the same.