The answer
NKBA benchmarks mid-range secondary bathrooms at $15,000–$35,000; primary master suites at $45,000–$75,000+. Waterproofing standards (IRC P2709.2 & TCNA): Tile shower pans require ASTM D4551/D4068 sheet liners or ANSI A118.10 bonded waterproof membranes; liners must turn up walls >=2 inches above the finished threshold/curb over a pre-sloped mortar bed (1/4" per foot slope to drain weep holes). A 24-hour standing water flood test is code-mandated before tile installation to verify watertightness.
Sources
This answer is drawn from the standards and guidance below. It is general information about how these systems work — not a diagnosis of your property.