It's a false comparison.

How many MIG-25s flew over the borders of the United States mainland during the cold war?

Yes the MIG-25 was a cheaper and more practical plane, but that wasn't the MO of the sr71.

I am not the one making those. If you read an article about how a Lamborghini Aventador was faster than a Nissan GT-R, you would go 'well, duh, it costs 20x as much'.