The P/S for the Rackbrute is missing; you'll find it under "Arturia" in the manufacturer list. And I don't think that Neutron belongs in there, since it already has a cab and power on its own. You want to use the not-exactly-cheap Eurorack cab space for things that DON'T have those. Or, a better way to put it:
Rackbrute 6 = $359 @ 171 hp (176 - 5 for the P/S). $359/171 = 2.10 (ish). This is the cost per hp of each space in the cab.
Neutron cost = $329. A Neutron takes up 80 hp, so $2.10 x 80 = $168. This is the cost to house the Neutron in the Rackbrute, which you would then add to the Neutron's cost, giving you an ACTUAL cost for the Neutron of $497.00.Honestly, you would probably be better off if you used the space the Neutron's stealing for a basic voice AND a good sequencer AND some modules to screw with timing for the interface with the Minibrute AND the Neutron. The above might look convenient, but it's going to cost you some real $$$ in the long run.
-- Lugia
Thanks very much for your detailed feedback, Lugia. I feel very fortunate to be able to ask experienced users these questions in this forum - it's a great learning tool, and saves beginners like me money.
Thanks for your point about adding the power supply to the build. I will have to add that to the rack.
I appreciate your thoughts on the redundancy of the Neutron. To be honest, this build will probably be a slow one, owing to finances, with the first rack (pictured) taking a while to come together, before stripping out the Neturon and adding another voice. For that, I thought of the Morphagene for its compatibility with Beads as a start.
I guess you may have already checked this one, but the combination of Morphagene and Beads seems like a real winner. Add to that a Pamela's and Akemi's, and I think I would be sorted for a while.
Once again, thanks a lot for your time and detailed comments.
All the best