Let me break it down if i wanted these things by other high quality hardware vendors.
so, BM eGPU Pro is 1359€ in EU, you get a TB dock and an eGPU.
If i want a dock, a vega 56 (new, not 2nd hand) and an external case from high quality vendors it goes like this:
400€ for Vega 56 (Sapphire)
500€ for sonnet 650W
300€ for Caldigit TS3+ dock
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1200€. the premium on black magic in that case is 159€. which is not a lot.
What do you need the Caldigit TS3+ for?! eGPUs are for T3 Mac anyway and if you use a MacPro 5,1 you can add the card inside.
ASUS eGPU 350€
Vega 56 350€
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€ 700
where are you buying your IT equipment?