Not surprisingly, many responded with the power cords as the most important one. Very possible because most of the homes are far from the ITU-T compliance, one the main culprit having no or a very bad grounding.
In terms of best return on investment, I would suggest having, whenever possible, a dedicated 20A line and have the grounding checked. Then spend the money downstream, starting with the ICs (staying within your comfort zone of your budget, upgrading slowing till you dont hear the improvement). In my particular case, after installing a dedicated line and improving the grounding, the difference between having a good power conditioner like the PS Audio PPP and without one is so minimal that I got rid of it; the overall performance on the system (using the same IC/SC) is very noticeable with the new AC line/improved grounding.
As for how much the allocation of the total budget should be I rely on the experience on fellow Goners. The systems section is very useful to checkout those with similar gear (say the same amp and/or the same speakers that you own) what type of IC/SC/etc they use in order to have a magnitude of the (extra) spending.
In terms of best return on investment, I would suggest having, whenever possible, a dedicated 20A line and have the grounding checked. Then spend the money downstream, starting with the ICs (staying within your comfort zone of your budget, upgrading slowing till you dont hear the improvement). In my particular case, after installing a dedicated line and improving the grounding, the difference between having a good power conditioner like the PS Audio PPP and without one is so minimal that I got rid of it; the overall performance on the system (using the same IC/SC) is very noticeable with the new AC line/improved grounding.
As for how much the allocation of the total budget should be I rely on the experience on fellow Goners. The systems section is very useful to checkout those with similar gear (say the same amp and/or the same speakers that you own) what type of IC/SC/etc they use in order to have a magnitude of the (extra) spending.