Thanks for comments! 
There are couple things that I might try:
- the original synopsis was "sometimes money can come out of test tubes", so I might remove the money from all but one tube (if you know any bio-med field you know that's the reality...)
- I was also thinking changing the money flow to gold flow, more symbolic
- there's some reflections that I want to accentuate
- background needs more definition
This image is kind of a photographic test also, so everything is done "in-camera" (with white cards & lights). I just remembered I moved the bg plane away from camera for some reason => more dof blurring :/. Moving it closer should fix things... I currently have 2 textured spots hitting the bg plane. One is over whole bg, the other is for hotspot. I think I'll try different textures for the spots also and maybe texture on background itself.
I'll be back with yet another iteration..
Juha