Yes, I agree, with preamps it's the same story - but it must be a good one: you don't have to spend a fortune, but you also can not cut costs where it can sacrifice sound quality.
I mean, most "prosumer" pre's are just crap, especially if you use dynamic mics.
Also not sold on the idea that some pre's give this magical sound - even though a majority of sound engineers claim it to be true, no one can prove it with measurements or blind test comparisons.
actually, they prove quite the opposite.
It has a lot to do with marketing - some artists would never rent a studio, if it doesn't have any major brand names in it.