Let's Talk Logistics.

So everyone seems to be pretty well versed in all things “military” on this forum. There are alot of good questions and even better polls, so I’m really surprised nobody has asked this question. What are the economic costs of purchasing 4th and 5th generation fighters these days. Alot of people talk about israel, serbia, and india upgrading their air forces or lack there-of…but what are the costs of purchasing a su-30mk or f-16d/e???? Just wondering if anyone had an idea???