The Lost and Damned DLC has been reduced to 800 MSP (50% off). This may be a permanent price drop.
The Ballad of Gay Tony DLC is still priced at 1600 MSP.
IMO, out of both of those, TBoGT is the superior DLC, hence the price difference, I guess. I don't mean in just the content (missions, side missions, mini games, etc.) but in context of having more interesting characters and developed storylines...Luis Lopez trumps Johnny Klebitz.