Digital BW, The Print

Hello,

My UT-R2 are only there since yesterday that I'm starting to worry 
about the day they will be empty...

What should I by? I've the full neutral set except Warm Yellow.
If I understand well:
Cyan & Magenta are the same density => Same ink here
LC, LM, Y are the same density => LC,LM Same neutral Ink, Y warm ink

So I could afford only buying:
- a bottle of neutral Cyan (also used for Magenta position)
- a bottle of neutral LC (also used for LM position)
- a bottle of warm Yellow
- a bottle of eboni black
- a bottle of photo black

Is it right ? On the site they have boottles for every position...

Thanks for your help,
François