What’s the deal with vendor SFP+ transceiver prices?

Is it literally just “we charge an arm and a leg because we can”?

I’m putting in a couple of new runs for some IDFs we are adding and the vendor SFP+ transceiver is $700 while a compatible one is $20.

Do you guys usually buy the vendor transceivers or do you save the money with compatible transceivers?

Last time we had a compatible one laying around and I used it with no consequences. Just wondering if there’s really any benefit. The vendor hasn’t made any comments about the current transceivers in the past so I don’t really see the point of wasting budget on no perceived benefit.