commercial pricing

[gaspastemania]

Got to put a price in for a school extension about three weeks worth of work .Extension on existing heating which is in screwed iron and altercations and refit for boys /girls toilets which is copper piping.
keep scratching my hread over this one with labour figures for plumber + labourer . What would you guys think on three weeks of commercial?

 

[SafeGasInstall]

if I was of a need of the job will go on £200 for me and a £100 for the labour and pay labour £60 anyway !
other ways will go for £300 and £120 for labour and labour gets £60 anyway ! +all materials and allow 2-days on top !