I don't know if people would call it luxury but I love my 2007 MGM Ultimate (leather interior, heated seats, air suspension, power moon roof). Got it for $24k CAD. Could have got a 2005 for $15k CAD but the 07 had full warranty and only 5000km on it so I couldn't resist. But a 03-05 would be in your price range and they are a very reliable car.
Compared to similar lincoln's the only thing I notice the lincoln had was nav. The rest of the interior was basically the same and the ride is the same. Lincoln may look a little classier to some but the new MGM's look nice IMO.
EDIT:
MGM = Mecury Grand Marquis