Right, about 2x purchase price, but probably also at least 2x cheaper to run and maintain. But if you're not flying at NATO rate, and have short term vision, it's less important than the contract value, since that's the big one that will put a big dent in the budget plans.
It's maybe the most difficult data to get accurates on. It's mostly classified, especially for new types. You can probably get on a very detailed level with it. It takes a fair bit of research. Many variables with each source.
Maybe for your purpose it's enough to get just some cost per flying hour estimates instead of all the different cost.
Market prices are very difficult because it depends on many factors: equipment fit, weapons included, spares included, number of aircraft, production agreements, training, tech transfer, offset programs, financial terms, contract type, and so on, and then it's highly depending on the year due to interest rates, currency rates. Then you have development costs if not off-the-shelf or some change, upgrade included.