Was wondering which of these would perform better in low light. Have a near-mint D1x w/ 50mm prime and 28-200 tamron lens available to me for $500, which would be about the same price as the D40 + 35mm prime. This will be used almost solely for concert photography which will be posted online (mp doesn't matter, just great low light photos), with the intention of upgrading to a D90/300 whenever the price gets low enough for me to afford. Is the sensor just too old to be worthwhile, or might it be a better pickup than the D40? Lemme know what yall think! Thanks in advance, you guys have been extremely helpful in the past.