i-adjective
ridiculously expensive; stupidly expensive
Colloquial, emphatic expression for something unreasonably costly. Often used in casual speech or informal writing.
この店のラーメン、バカ高いけど美味しいんだよね。
The ramen at this shop is ridiculously expensive, but it's delicious.
あのブランドの服はバカ高いから、手が出ない。
That brand's clothes are stupidly expensive, so I can't afford them.
Compound of バカ (foolish, absurd) and 高い (expensive). The exact origin is uncertain, but it follows a common pattern of using バカ as an intensifier in colloquial Japanese.