TheitemsfoundinthePreliminariessectionofabillofquantities areusuallythemostdifficultandarbitraryofalltoprice.Indeed,if allthetenderers'pricedbillsforanyoneprojectcouldbeexamined, thissectionwouldproducethegreatestvariationinpriceswitheach estimatorhavinghisownideaastothescaleandextentofthecosts. involved.Thenatureandtheconditionsofcontractofeveryjobare differentandtheitemsencounteredinthePreliminariesare thereforenecessarilyuniquetoeachparticularproject,andwhilst recordsfrompreviouslypricedjobswillbeusefulandwillassistin somemeasureinestimatingthecostofthecurrentsetof Preliminaries,theycan,atbestserveonlyasaguideandeach Preliminaryitemmustbelookedatindividuallyandpricedonits ownmerits.Thereisoftenagreattemptation,particularlywhen timeisshort,tolookbackatapreviouslypricedsetofPreliminaries whichappearsonthefaceofitsimilartothatunderconsideration andextractpricesforuseinthecurrentjob.However,whereasone setofPreliminariesdoesindeedoftenlookprettymuchlikeany other,carefulexaminationwillnodoubtrevealextrarestrictionsand limitationsimposeduponthecontractorwhich,ifoverlooked,could losehimagreatdealofmoney.SinceeachsetofPreliminariesis differentfromanyother,thebestwayofillustratingthepricingof thissectionofthebillistoconsideratypicalsetofPreliminaries (Example1)foraspecificcontractandthischapteristherefore devotedtothatend.