Don't know what year or engine it is, but Autolite Iridiums are probably good plugs for it.
They are 4.5x on Rock Auto for the for most Fusion engines, and there is a 2.50 a plug rebate, so 2 bucks a piece.
I assume this is the same one you asked about the transmission fluid and got some really bad advice, so take it for what it's worth.
97 Mark VIII LSC/Silver/Gray leather
97 Cougar 4.6 Sport/White Opalescent Tricoat Metallic /Gray leather down but not out?
89 Cougar LS 3.8/Oxford White/Gray velour/HG need replaced AGAIN
00 Grand Marquis LS/Vibrant White/Gray velour
63 Falcon 302/black and rust/shed isn't moving
82 F-150/Oxford White/dumb VV carb doesn't pass emissions