noun
someone out of one's league; something beyond one's means
Used for a person (often a romantic interest) or thing that is too good, expensive, or high-status for oneself. Conveys a sense of being outmatched.
彼女は俺には過ぎ者だよ。
She's out of my league.
この車は過ぎ物で、とても手が出ない。
This car is beyond my means; I can't afford it at all.
高嶺の花 is a set phrase for an unattainable person or thing, often romantic. 過ぎ者 is more colloquial and can refer to any person or thing beyond one's reach.
Compound of 過ぎ (sugi, 'exceeding') + 者 (mono, 'person') or 物 (mono, 'thing'). The exact historical derivation is uncertain, but the meaning is transparent from its components.