To stop people using them as a price quote service. When I was in the trade you waste alot of time giving estimates for watches you haven't seen. You assume perfect and go high they moan when it needs work, you go low to factor in refurbs or repairs and they think you are a shark so having it right there is the best option and stops you wasting time on dead business. The other really annoying one was if you put price on application and everybody would ring up and ask you what the price was even though they had no intention of buying it if you don't wanna buy it don't bother asking what the price is.