[chrispedersen]

One other factor figures into the equation:

Research.

Acashic is conj 5, as I recall. So nations that are on a research fast track, and for whom the conjuration tree is advantageous, (like Ryalleh) not having to sidestep research is advantageous.

So, making a few assumptions:
If gems are set at 60%, and average gem density is 1.5 per site.
thats roughly 1.8 gems per province.

Site searching could take up to 8 searches to find them all. If your only mages available are 8rp mages - thats costing you 64 rp and 16 gems... vs 20 gems and 8 rp.

However you recover the gems faster as well. During those 8 turn of site searching you will recover on average 11 gems due to faster discovery by acashic record.

Cost of acashic should scale with gem frequency = )