please see my answers to your questions:
Retrofit with BM4400-series:
1/ Price for the complete cabinet can be reduced to 8.995,-€ (EXW Nürnberg)
2/ I think BM China can come for commissioning. I think 2-3 days will be needed. Please check this with BM Shanghai directly.
3/ End customer must prepare installation of the cabinet (electrical and mechanical)
I have spoken internally regarding the 1 by 1 replacement of BUM63. We can offer you 7,25% discount on the given price of 8.039€ (EXW basis).
Please let us know your decision.