I agree with repairing the existing one. It seems the failure point is the headlight relay which is an undersized solid-state piece. The addition of a BOSCH or P&B relay will add more then enough capacity for current and be a permanent fix. I don't know if the replacements have different components or if they're the exact same prone-to-fail as OE. Personally, I would not trust our local dealerships with a potato gun let alone digging under my dash (or yours) with many of the aftermarket goodies we all add. It seems like more problems would arise from a small cure.
'04 Silver Marauder w/ sunroof - HID lighting, JL Audio / Eclipse DVD/NAV/iPod/camera, 4.10's, 2" drop, Progard Bumper Baffle, Delete tips, Billet Pedals, BC4E dead pedal, Lidio Tune, Mach1 chin spoiler, K&N CAI, TCE lines, Super40's, tinted tails, SS Inserts, Heinous Control Arms, Real oil gauge, lighted door handles. Currently installing Eaton M112.
2004 Mercury Marauder
Born March 2004, adopted October 2005. Sold January 2012, adopted AGAIN January 2016
2,187 of 3,214
997 in Silver Birch
448 with light flint interior
304 with heated seats
336 with sunroof