Reply to noobie question - do you buy older tracks? (not talking about hits)

all my life i've been a crate digger. from my early days as a scrawny kid looking for that one live bootleg of his favorite rock band to my love affair with electronic music that has grown over the past 5 - 6 years. why it took me so long to believe of dj'ing myself, i have no idea. but here i am

as i make the transition from a listener of mixes / podcasts to actually building my own library however, if i run across what i believe is a hidden gem but i discover the release date is two or three years ago, i find i have this hesitation to buy it. like i'm breaking some unwritten rule.

i love long deep house sets. it's not a genre that really focuses on recognizable anthems to begin with, so it some ways it seems like it shouldn't matter.

but i was just curious to get the opinion of the more experienced folks on this board - when you're making a mix, does every track have to be from the past 6 weeks? (exaggerating, but you get my point). what is the average shelf life of the tracks you buy? is there some cutoff point for a tracks release past which you wont buy it?

anyways, thanks in advance from a noob.