Cheryl,
I think you will find that Mike is talking about, what I call the Hi Lite areas only, i.e. the open uncovered central area and walk through from the doors. Dont forget that if you are doing it for free, are you really going to spend a lot of time doing EVERYTHING, that you would do, on a job you were getting paid for. Like they say you get what you pay for, there's NO free lunches, its simply a sales ploy. Many may not like this fact, but in the real world thats how it works.
Personally I dont like running offers of any description but if I get beaten down in price say by 30% I either walk away or I do 30% less of a job, they dont get it both ways. If they want the full works they pay my full price, if they want to compromise on price - I compromise on the job. Fortunatly these situation are few and far between, but some will try it on.
Dave.