Ok I appreciate it was a slightly vague question. I find it difficult to explain my rendering time as it is so varied. I would say an average render at approximately 4000x3000 pixels may take 1/2 -1 day.
I did mean £ sterling yes. I feel if i could 1/2 or 1/3 my rendering times i would be over the moon and spending £1500 on upgrades would be more than worth it.
I have considered a building a render farm as used PCs at slightly lower specs seem to drop considerably in price, i assume this is because everybody is constantly striving for the best of the best!
Something else that i see has been discussed often is the GPU rendering ability for VfSU2.0.
(Another vague question coming) I understand the more nodes = faster rendering however would using Vray 2.0 with an upgraded graphics card 'significantly' reduce the need for lots of nodes.
I think my real problem is i'm finding it difficult to compare components performance with render time.