Why I am against the Oracle:
Lets put to the side for the minute the inherent risk of playing on a crooked roulette wheel against a spinner who is wearing a graduate of evil doctoral school T-shirt, and think about the value of the oracle.
Cost of Oracle:
75 Hammers (assuming hook up marble) = ~1 settler
80+60=140 base beakers
A likely delay in hooking up city two fo trade route.
A likely reduction in optimization of worker turns.
Benifits of Oracle:
One of:
CoL = 350 base beakers
Math = 250 base beakers
Alpha? = 300 base beakers
I beleive a base beaker = about 1.45 real beakers under these settings, assuming a prerequisite bonus in play for all these techs, so lets just make it 1.5 for simplicity.
Substracting away the invested costs of 140 in the religious techs, we are "gaining"...
COL: 210*1.5 = 315 beakers
Math: 110*1.5= 165 beakers
Alpha: 160*1.5= 240 beakers
That at the cost of the 75 beakers and the other slight penalties listed above.
What techs do we want NOW?
The first order of buisiness is to grow an empire that can sustain a war and continue to tech to at least democracy and a corp/corp resources. This means we need to rex and/or grow through war an expand in an economically stable way. What are the first techs we need for that?
1- Math.... Math will allow us to chop (WT (and I) hate chopping before math... Activating math chops helps power the growth dramatically.)
2-Currency for the trade routes.
COL is needed at some point, but I usually do not build my first courthouse until around city 12 or so is up, so it is not an immediate priority.
Timing of techs...
We are realistically looking at a turn ~ 28 oracle... If we take COL with that, we are delaying both math and currency by the time it takes to research the religious techs (at our ~turn 25 research rarte). OUr research rate will be:
Palace = 8
Copper = 1
Marble = 3
Center = 1
Sid =1
So 14.... 140 costs * 1.5... That means math and currency come in 15 turns later... COL earlier is of little use (the religion is not a significant bonus in my eyes.)
So, if we did go for Oracle, I would argue the correct tech choice is math, despite being the cheapest.
Now, if we simply forgo the Oracle and go stright for math... We are currently researching at 10 per turn (including sid's beaker)...At turn 25 we will be at 14... Lets make it 12 on average for a roungh number. 12*25=300...It cost 375... 75/14 = ~5 with some optimization...
So, we can get math at roughtly the same time (maybe two turns slower) by just researching it direcltly instead of going for the oracle, and that is WITHOUT including the benifit of the second city... With that incorperated, we likely can get math at the same turn by direct research, and then it would be garanteed, and independent of the roulette wheel (tm)
Assessment:
If we go for math and get it with oracle...
At the turn oracles come in...
-We are bassically at tech equality with the math directly approach (since the religious techs we have are useless)... True, in the oracle approach, we will have some 160 beakers invested into CoL or similar, but it is not of immediate payback.
-We essentially have one settler, and thus one city left.
Even if the result was garanteed, I dont think I would take it, and the result is far from garanteed... If we gamble and lose, we are way worst of... So we are risking alot for the potential of an almost intangible gain if at all...
On the other hand, if we Oracle CoL, we are quite a bit better off beaker-wise, but we have delayed Math and Currency by 15 turns...
The value of this currency delay is pretty easy to estimate... We are talking about the period of about turns 50 to 65, so we should have about 6 cities at the time... Currency will be worth 6 coins per turn for those 15 turns = 90 goins, or about 110 beakers (prerequisite bonus.)
Math earlier is more difficult to quantify, but as long as it is worth at least some 50 beakers (which I think we all would agree to), then the math and currency first approach will catch up.
Bottom line
With the above in mind... Even if you could garantee Oracle was safe, I dont think I particularly want it! Compairing that to the risk of missing it, and I think it is a very poor gamble.