I don't know much about that kind of lighting, but I do suspect your estimator sees you as a sheep to be sheared...or he doesn't want the job at all and gave you a very high price in the hope you won't pay him to do it.

Personally, I would never have a 110v light under any circumstances...no more than 12v, ever. My lights are different in that the clear lenses are installed through the pool wall and the light is inserted into it, from behind, and is never immersed. The lights are also 12v.