1 On average, a Bath Fitter product, along with professional installation, is going to cost about $2,000 to $7,000+ for typical bathroom jobs.2  It will depend on the features you want and what type of setup you have. According to some members on MommySavers.com, they paid anywhere from $2,000 to more than $7,000 to have a Bath Fitter installed. 2  During the process, a Bath Fitter representative comes to the customer’s home and explains the Bath Fitter technique.