
When lacking cultural goods or diplomacy to unlock an advancement, the player can use diamonds. The total amount of cultural goods needed to unlock all advancements is 938. It can happen that one of the possible goods requires 0 amount and is not shown to the player. Just sayin'.The table below shows the total amount of cultural goods and the possible type of goods needed for each advancement. But I had to build 50% more Viking settlements for, basically, the same reward provided by the Egyptian settlements.

Only 2 of each type were completed to the highest level. The end result for my city is that I have the same number of Obelisks and Runestones: 3. One final comparison: you only have to build 10 Egyptian settlements to get all Bathhouse and Obelisk upgrades, whereas, you have to build 15 Viking settlements to get all the Yggdrasil and Runestone upgrades. It's an absolute slam dunk to complete the Egyptian settlement long before the first expiry date for the max number of Obelisk fragments. And the Obelisk is the clear winner of that comparison. But the last and most important thing to consider is how long it will take you to complete the settlement in order to obtain the most number of fragments of the Runestone and/or Obelisk, which are time dependent. The last extra reward is a 6% defense boost for the attacking army from the Obelisk and a 2% attack boost for the attacking army from the Runestone.

On the other hand, the Runestone gives out medals when you get to level 3 (24/day for my city in the OFE). 2) they're both the same size (2 x 2) and give the same number of fps (2) at the highest level but, for some reason, you only get 1 random good from the Runestone and 4 from the Obelisk: it's a puny difference but over a year it adds up to over a thousand goods. So it's a little easier to max out the Obelisk. 1) the Obelisk only has 4 levels and the Runestone has 5.

The Viking settlement gives you fragments of the Greater Runestone and the Ancient Egypt settlement gives you fragments of the Ancient Obelisk. Don't forge to compare the extra rewards.
