Hi, Modron! Music is always an excellent investment.
I’m actually Blending on a PC (Xeon-based) system. Macs seem very nice, but the workstations are still quite pricey 
Quad-cores seem to have come down quite a bit in price. 8-core systems should come down more as well, as newer / faster / more-cores-per-chip systems become available.
I do find Blender internal render has always been dependably fast even on my laptop, and with each new version of Blender it feels a little faster.
This project was particularly expedited through the use of render layers - three of them: foreground (internal view of control room), planet being converted, and then a separate layer for energy glow.
Without the render nodes, this would have taken much longer to render.
Wherever possible, I try to take any render time saved from that kind of workflow and reinvest it in the “tweaking” phase, which in this case lasted nearly four hours 
One thing in particular I enjoy about the weekend challenges is that the time constraints compel us to come up with very short-term solutions and to make somewhat snappy decisions.
In many ways that general approach has helped keep a good part of my Blender works (and not just in the wc) more spontaneous and less prone to over-editing.
I’ve ruined more than a few projects by spending too much time on them long after I should have moved onto something else, but there are still projects, such as this one, I wouldn’t mind returning to in order to develop further some areas where corners had to be cut to stay within deadlines.
With Blender, the paint never dries and the clay never hardens, so we can always go back and make something worse better or vice versa 
RobertT