The step from a normally aspirated v10 to a normally aspirated v8 is tiny compared to moving from that same V8 to a turbo charged V6 with an additional energy recovery system and much more stringent fuel restrictions.
The teams essentially write the regs. They could all agree to close down many avenues of aerodynamic development and the costs would plummet. 2014 is unusual (in recent years) in the amount of money going into power-train development. Usually the majority of expenditure is on aero-voodoo which is hugely expensive.
I think flo-viz is at least $19.99 per can, maybe more.