Does anyone know how much a 2006 s40 with blown engine would sell for? Besides the engine everything else is in fair condition?!

 

you can use KBB.COM to find a "market" price in your area for the S40 assuming the engine was ok, then subtract off a cost to swap in a replacement. used engines can be estimated by searching car-parts.com for a used engine in your area, plus add in some estimate for labor (say $1000 or so)