noun which may take the genitive case particle 'no', noun
dirt cheap; super cheap; bargain-priced
Colloquial term emphasizing an extremely low price, often used in advertising or casual conversation. Functions as a noun or no-adjective.
この店は激安だから、いつも混んでいる。
This store is dirt cheap, so it's always crowded.
激安のスマホケースを見つけた。
I found a super cheap smartphone case.
Compound of 激 (intense, extreme) and 安 (cheap). A relatively modern colloquial coinage, likely from advertising or youth slang.