I'm sure this has been covered before, but I'm having a hard time finding the information given the very long thread.

So far I've always purchased SAF with cash, but I'm sitting on a decent amount of miles and for my next flight this Friday I'm considering using miles. I assume you're getting less value if you use miles instead of cash, is that right? What does that loss of value look like?

These are the offers I'm getting with AF:



KLM strangely isn't showing a miles value - I was sure you could use miles with KLM as well?