I didnt think it was as high as 80 to balance their budget, hardly struggling exactly but Saudi Arabia is also issuing their own bonds. I do think to do such things they might be better to demand payment in their own currency and if Trump continues his alteration of long term policies who knows. I know Iran has big problems with higher costs, lack of investment for many decades. BP is moving into Iran despite losing half their company there in the seventies, must be extreme.
Actually I was wrong. Saudi Arabia needs a crude oil price of $104 per barrel to balance its budget (perhaps they can adjust slightly by increasing the production). There is not a single oil producing country, which can survive at $55 per barrel in the long term. Check this:
But this is a two-dimensional view of a multi-dimensional issue.
This looks solely at oil as the changing factor in a balanced budget without regard to all of the other variables which determine whether or not a budget is balanced. For example, it ignores all other sources of revenue and budget cuts and focuses solely on a static budget that doesn't change, and all other sources of revenue are assumed not to change as well. It's far less important if the country can "balance the budget with the current price of oil" than if the country can
produce oil at a profit at a particular price. Then, by definition, all oil production decreases the budget deficit. Concluding that a country cannot sell oil at a particular price because it doesn't allow them to balance the budget is not a sound conclusion. It's only an issue if they can't make a profit at the price.
The bolded bit is very true. The issue with Saudi is that it doesn't have a balanced economy, it is entirely oil driven.
Whereas Iran's economy is much more diverse - they export Caviar for example, plus Persian carpets, they have good agricultural land, so they can export food as well. I'm pretty sure Iran will win it's battle for domination against the Saudis because their economy is more diversified. The figures you have for the level of oil price needed to balance Iran's economy are from before the sanctions were lifted. Now sanctions are lifted, they can export lots of other stuff too, which helps them cope.