1 Total cost for removing the old tub and installing a new one can run $1,500-$5,000 or more but averages $2,500-$3,500 depending on the ease of access, local rates, the quality of the new fixtures, and the extent of the repairs/replacements for the walls, plumbing and flooring.eplacing a fiberglass one with an acrylic whirlpool one. The estimate I got was for $3900.00 with me buying the tub and with a notice that the costs could go up if they have difficulty setting the tub. The tub cost $800. I am trying to keep costs down, so I am having them minimize the tile replacement.