well, as a comparison, the price to swap an RB26DETT into a 240SX is not too far below or above $10,000 usually, and that engine would probably go in relativley easy compared to a V8 that's almost twice the litre-age. i would say at LEAST $10k, but that also depends on how much a VK would cost. i would think they would be pricey...but i'm not too sure.
also, because of the weight of this engine, it would totally throw off the handling and balance of the 240SX you would be putting it into. this would pretty much be a straight line car and that's about it.