Quoted from Viper Jon - "Prices we got ranged from $6800.00 to $2900.00 for the SAME thing. All licensed guys (they have to be for town demo permit). Amazing 4K difference. Was really surprised at that large a variation I figured they would all be pretty competitive. When it comes to this non skilled aspect I'm just taking the lowest guy period. They have to be insured and licensed."
In case you were still wondering why the big difference in estimates you received.....
There are so many variables in presenting a price to the client. I do demolition work so I will give you some insight as to some of the more elusive reasons. Number one is how bad the contractor wants the job. If the contractor has had a slow month with no projects on the horizon he may bid very competitive to make sure he gets the work. On the other end of the spectrum, the high price you receieved may have come from a contractor who was very busy and really didn't need the work - but he put in a price anyway on the off chance you chose him and he gets to ride the gravy train all the way to the bank. Some contractors have even been known to underbid the actual cost of the project and take a hit - just to keep the other guys from getting the job! (Silly reasoning I know)
Another variable is in the disposal of the material. Some contractors only have a shop and equipment and rely solely on disposing of material at a licenced waste site. They get charged by the ton for getting rid of your old garage. On the other hand, some contractors own property and "dispose" of the material at their place saving the cost of disposal. This method, while generally not legal in most jurisdictions, allows the contractor to outcompete his rivals by saving thousands of dollars in disposal fees (Burn the wood and bury the concrete when no one is watching)
There are just so many other reasons why prices differentiate wildly.
Another reason is in the post-project cleanup, i.e. the higher priced guy may have alotted budget for thoroughly cleaning up of site, removing ALL material and grading the location nicely with a dozer, while the other lower priced guy may just pull up all the big pieces and leave you with a bit of a mess - ("Oh, you want ALL the small shrapnel cleaned up and the ground graded neatly????... I see....well that will be EXTRA Mr. Viper Jon
)
Thats why its good to read the fine print or thoroughly discuss the scope of the project beforehand with the bidders - to make sure you can compare apples to apples.
I can think of a hundred more reasons, but I'm starting to write a novel here and should stop