The NL central is crap - agreed. But they should start building long term...don't trade what very very few prospects you have to make a run at a division you likely won't win (nor the wild card) and even in the very unlikely event that you did, you'd get swept by the Dodgers.
Sell now, build your farm, accept crapiness for this year and next, and rebuild.
F'n A, I should be a GM