Indeed, I don't think we can do better! ( Processor that goes higher in GHz , Higher graphics card, bigger ram) I also asked for a quote for a Watercooling since the processor will heat up with this high rate...
For the moment, this is only a quote but we are at 6K € / Workstation.
In fact, rechecking against the configuration of @ronathan we have 32 GB of RAM instead of 16 GB which seems a bit light to me. With this configuration, we are about half the price compared to you.
It depends on your network. We have a very slow network, the difference is double between the direct opening (SSD of the PC) compared to an opening on a network.