Depends on the package, based on Qatar's recent purchase of their F-15QA, they bought 36 F-15's for $6.2 billion so that means each jet including support, equipment, training and armaments cost around $172 million. But keep in mind, this is the first time Qatar operated a US fighter so that means they have to establish all the necessary infrastructure and training to operate them. You could also look at the DSCA for Saudi's F-15SA purchase where each jet actually costs $200+ million but if you look at their DSCA list they basically bought a lot of spares, hundreds of armaments. I mean Saudi's DSCA list had them buying 84 jets but they also ended up buying 170 AESA radars as spares so thats why Saudi's price were a bit more expensive per jet.
So basically the price depends on the jet you buy (every variant can usually be different based on each country's requirement) as well as the amount of spares, equipment, weapons, training you buy
So to answer your question honestly even though this isn't entirely accurate, based on Qatar's purchase and Qatar's situation, $1.2 billion gets you 8 jets? But again, we're not Qatar or Saudi.
Reference:
Qatar F-15QA deal:
https://www.aljazeera.com/news/2017...s-62bn-contract-qatar-15-171223192108186.html
https://www.dsca.mil/major-arms-sales/government-qatar-f-15qa-aircraft-weapons-and-related-support
Saudi F-15SA deal:
https://www.dsca.mil/major-arms-sales/saudi-arabia-f-15sa-aircraft
To be honest, what we need to think about is not just the acquisition costs since Indonesia itself has rarely paid for big tickets up front, we mostly pay in credits. This is just my opinion, better to buy expensive now, but benefit from the lower operational costs, better efficiency and commonality in the longer term.
I wasn't really planning on looking too deeply into this, just a quick estimate of how many F-15s we can reasonably expect to get if we divert the budget for Su-35 to F-15s... Thanks for the references..!
However after looking into it I found some mistake in your cost assumption based on the article :
The value of the Qatar purchase for 36 F-15s is actually not USD 6,2B, but 12B... The 6,2B first mentioned in the article is only the amount awarded by the Pentagon to Boeing to manufacture the 36 F-15 airframes and is not the actual cost of the contract with Qatar.. and additionally, according to the DSCA article, the current purchase is actually part of an even larger purchase of up to 72 units for an estimated total value of USD 21,1B.. So the total cost for this initial batch of 36 units for a cost of 12B is quite correct.
So based on that, USD 12B/36 = ~333M / unit.. for a complete package..
If we take the Boeing contract cost it will be USD 6,2B/36 = ~172M / unit.. but note that this is for the airframe manufacturing cost only, not including anything else..
So with only 1,2B how much can we expect to get..?
If taking the Qatar complete package we will get : 1,2B/333M = 3,6 --> so between 3 or 4 units
If taking the Boeing manufacturing cost it will be : 1,2B/172M = 6,9 --> so between 6 or 7 units..
But there's no way we or anyone else (other than the US) can buy it on airframe manufacturing costs only... so what might be a reasonable package price for us...? The Qatar package cost seems split about 50:50 between the actual airframe cost (6,2B) and the rest of the project cost for support/infra/spares/training/etc (5,8B)..
So since we are not as cash rich as Qatar let's say we spend only half the cost on support (5,8B/2 = 2,9B).. it will then cost us about 6,2B + 2,9B = 9.1B ~ 9B... 9B/36 = 250M / unit.. so for 1,2B we will get 4,8 --> between 4 or 5 units..
But again we have to note that as in any other trade, the more the quantity we order, the cheaper the unit price we get... So the unit price for 36 units likely won't be the same for only 4 - 5 units.. so in the end, for USD 1,2B we will likely only get 3 or 4 units max...
Also do note that Qatar then spends an additional USD 1,1B for supporting services in a separate contract.. so for the 36 F-15s they have actually spent 12B + 1,1B = 13,1B ... almost certainly not affordable to us for now...
No it'll be a lot more than that. The reason being the F-15 shares a lot of commonality with the F-16 so we wouldn't need to build up that much new infrastructure. Look at Kuwait's SHornet order. 28 new jets that costs $1.5 billion. It's that low because they already operated the legacy Hornet and thus didn't need to build up new infrastructure.
Simply impossible for new F-15s... and I'm quite baffled why you would even compare it to an F-18 purchase in the first place...