I'd be keen to hear, I asked a dealer and seems they only would do it as a warranty claim.. weird, mine is nearing 2 years old 6000+kms so one would expect it to be not at its best now.
If anyone is still curious my dealer was saying 800-1k depending on where you get the battery from. Orbea might have some left but it's Shimamo who is now supporting that battery. I am just going to ride it till it dies and change it then.