No!
I don’t work for free.
In my experience companies, who ask questions like this neither have money nor interesting projects.
And even do I think it is ridiculous till a certain degree since no one would sit down into a restaurant and would ask if he can, could get an appetizer for free.
I can understand the wish to test something out, before buying it.
So let me explain why this doesn’t make sense at this point.
This here is the Golden Triangle, one of the fundamentals of Project management. The core statement of this illustration is, that Scope of Work, Time and Cost are the Main factors for quality.
Or in other words, with this you don’t compare people, you compare the time they are willing to put in without any return.