not bad on the labor, it could have been a lot worse. I looked up the part and Mercury doesn't sell the trim motor by itself, it list a trim kit for $1171.00
for the design 1 and $644 for the design 2. Arco(good aftermarket) retails for $612. There's decent mark up on that pump. The dealer didn't screw you, Mercury did by having that trim motor so high, everyone else bases their parts off of OEM