NOT a full story, rather, a mechanic for sidestepped lottery winner trope. Really a somewhat stupid idea, with own levels of disbelief, but hear me out.
So, a guy (but not necessarily guy, gender reversal or whatever may work), he could be in college or high school, whatever... he desperately needs a pair of formal slacks (or whatsoever other piece of clothing) goes into a thrift store (I envision "any single thing for $5" type, dunno how yours operates), and randomly find one that fit them perfectly. It may, but don't have to be, an originally ridiculously expensive cult designer item.
Now, there's certainly a story where the sheer confidence given my the flawless garment perfect for the upcoming occasion sets him on the right path, but I have something a bit different in mind.
Examination of a mild annoyance with the piece of clothing, reveals a tricky additional pocket only accessible from the inside (I envision in the space between the true pocket and the side seam, but other options exist), and a small (sturdy) object in it.
Why, so that's how he got the magic mind control ring! Or whatever. It could be a key of a bank safe, could be memory card with a bitcoin wallet or secret documents on it.
Anyhow, the thing is likely rather seemingly worthless on its own without the right guess and research, but then becomes the key to glory. Comes with the added mystery and side plot of how it got lost and who wants it back.
If similar tricks have been used to death already somewhere, I apologize.