If it was a good regular customer it would be £250 and i would take my time and leave just after lunch,anyone in there right mind and i`m talking customers will know this is a really S****Y job and it will cost to get it done.If your quoting £120-150 why take it on say you can`t do it and carry on with your regular work,you blokes are not quoting trad prices and we should all have a rule that we should.If it was a one off with maybe a call back once every 2-3 years then i`m putting off my regular work so they will have to pay double,in all seriously i would charge £350-400 as a one off.