Is there a light civilian helicopter capable of a 250 NM trip without refueling?
I would need a definition of the word 'light' as it is a little relative.  Most light turbine helicopters eg a Bell 206 JetRanger or a Hughes 500 will do this job just fine.

It is a little difficult to locate a reciprocating engine powered helo that meets those criteria.  The Guimbal Cabri G2 and the Robinson R44 would be my choices for that but cost over $300,000 a piece.

The Schweizer (now Sikorsky) S333 would be another good choice.  It is a light turbine helicopter and can be obtained for just shy of 200,000 USD, though you may be required to put another 100,000 USD or so into it.