This is a very subjective matter, but if it exactly something I want and I can afford it, nope, money doesn't matter.
Being "exactly" what I want is not an easy standard. Size, condition play a major part, but there is also the intangible mojo thing. It's hard to put a finger on that and is an entirely personal choice.
But I'm not the type to rotate a collection. I pretty much buy and hold. So if I spent "a lot" on a bike, I hold onto it until I get my "money" out of it. I don't worry about if I recoup how much I spent. Same goes with tires. I buy them, ride them until threadbare, then get some new ones. Only difference I have yet to wear out a bike.
I will pay what it takes to get what I want.
As long as the $$$ come out of my bike fund, the world continues to turn.
FWIW Try building a new MTB from scratch. My new Yeti will put me in the poor house way before a nice vintage bike will. In fact, I could likely pick up at least three-four high end vintage bikes for a similar price.