Price is the easiest thing to compare and the least useful. These are more revealing.
Who is actually on site?
Ask whether the person quoting will be there during the build. Work slips when the estimate and the site are handled by different people.
Is electrical and plumbing in-house or subcontracted?
Subcontracted trades work to their own schedule. That is where most delays come from.
What is the licence number?
It should be given without hesitation and be verifiable with the Guam Contractors Licensing Board. Ours is CLB22-1786.
What happens when something unexpected turns up?
Rot, old wiring and failed waterproofing are normal. Ask how a change gets priced and approved before it happens.
What does the punch list look like?
A job is not finished when it looks finished. Ask who walks it at the end and who signs it off.