You slam on the brakes and hear only metal on metal. Time to get the brake pads redone.

Mechanic tells you it should cost around $100. When you come back it's $200. Took longer than he thought, replaced a lot of parts. He's very nice about it but somehow you feel you've been taken.

What can you do? Next time get a quote.

A friend of mine who runs a multimillion dollar factory tells me, "An estimate is not a quote." What he means is that a quote is a solid price the company must abide by. An estimate is a rough figure subject to change.

To be fair, many jobs can only be estimated. Until an exact diagnosis is made, a firm quote is not possible. The workman needs to know precisely what the problem is and if there are any extras involved.

Let's go back to the brakes. A quick free inspection should show whether the pads need replacing and if there are any related repairs such as worn hoses or leaky cylinders. A mechanic can look these up in a standard pricing book and give you an exact cost. That's when you ask for the quote in writing.

And leave your phone number. If something expected comes up ask him to call before he goes ahead with any extra work. But a pesky electrical problem might be very hard to diagnose, so don't expect to get a quote.

Dental work, many auto repairs, printing, construction jobs and home improvement can all usually be accurately priced.

Construction can sometimes be tricky. A price for work on an older home often cannot be accurately determined until the workman tears open a wall. In this situation you would be best to pay by the hour, but keep tabs on the work as it progresses.

New construction can be accurately quoted. If you are getting a shed built outside your home, you should expect a price that you can bank on.