Huw at Brickset mentioned some sets at Target that will be heavily discounted on “Black Friday” (day after Thanksgiving in the US), including the 7048 Troll Warship. If you’re after some of the other Troll sets, they are being heavily discounted in other areas.
One of them is the 7041 Troll Battle Wheel, with 508 pieces and 6 minifigs, and I found one at a Toys R Us in the Houston area for $29.98.
These are not being offered through the Shop@Home LEGO site, at least in the US:
Sorry, item is not available in this country: United States.
As far as the official Toys R Us website, they are only offering LEGO Castle: Troll’s Dark/Moutain Fortress (7097) and Troll Assault Wagon (7038) so this is definitely an in-store thing. Neither the 7097 or 7038 seems to be discounted.
There have also been some older Agent sets as well. Some of these sets are not showing up on the Toys R Us website, and you are best checking through an in-store price checker.