A bathroom is bought twice, and most dealers only sell it once
Sanitaryware supply splits naturally into two purchases separated by months. At plumbing rough-in the site needs concealed cisterns, diverter bodies and inlet fittings, which go into the wall and are never seen again. At finishing it needs the WC, basin, taps, shower, seat and accessories, which is where most of the value sits.
The dealer who supplies rough-in has a structural advantage at finishing, because the concealed body already in the wall constrains what can be fitted over it. Yet an enormous amount of finishing business is lost simply because nobody called back when the site reached that stage. It is the single most fixable leak in the trade.