That sounds too good to be true.

Literal

Story [subject-が] too-good [emphasis-よ].

A blunt, gut-reaction exclamation. 話がうますぎる ('the deal sounds too good') uses ~すぎる to convey suspicion that the offer is implausibly favorable. The sentence-final よ delivers the punchy disbelief without any grammatical hedging — instinctive skepticism in a single beat.