Caveat Emptor, buyer beware
Generally speaking most quotes (providing they are based on the same criteria), will be within five to 10% of each other. Given that material costs are usually around 50% of the overall cost a quote that is considerably lower than the others should be discounted straight away.
The other thing to do is carrying out a little market research. A quick look at web sites that promote trades or organise quotes will reveal a lot of ‘businesses’ with professional sounding names. But often these businesses don’t have an address and can’t be found through internet search engines, white pages and the like. More often than not these ‘businesses’ will be backyard operations, run by people who aren’t qualified, use questionable materials and most worryingly have little cabinet making experience. Use them at your peril.
Finally, just because your project is small don’t assume anyone can carry it out satisfactorily. If things go wrong and you have to take legal action (and this occurs more often than you possibly think) please bear in mind that courts will usually require a professional report on the work. If that is the case you may find that your ‘cheap’ price may well blow out by several hundred dollars and you will incur considerable inconvenience. A careful read of the articles in this section may very well help you avoid big problems in the future.