Making about $34,000 a year, filing as a single person and taking the standard deduction, the Insight $2,000 deduction equalled me paying $300 less in taxes.
I'm not sure if the hybrid deduction is $2000 for 2005, though. I know it was being phased out even in 2004 (I think it was going to be only $1500), until Congress specifically voided the phaseout for 2004, but I'm not sure if they voided the phaseout for 2005, too. So the deduction you get might be only $1000 or $500.
Used is a good option, I think. Why not fly to the place where the Insight is and drive it back? Plane ticket = $350, gas on trip back = $100, hotels on trip back = $150, boost in MPG from so many highway miles: priceless...