A quote is a description of work before it is a number. These are the six things to find in one before you compare it with another.
1. What is behind the cladding
A price that names the cladding and not the barrier is a price for a facade. Ask what barrier, whether there is a cavity, and how the base drains.
2. How flashing is priced
Flashing at openings, penetrations and changes of plane should be its own line. If it is inside the square-foot rate, you cannot tell whether it is included or assumed away.
3. What the transitions are
The roof-to-wall, the deck, the window head and the base are where water gets in. A quote should say who is responsible for each.
4. Whether soffit, fascia and gutter are in
They are frequently a separate scope and frequently forgotten until the wall is finished. Ask explicitly.
5. What happens after the walk
Ask how deficiencies are recorded and closed, and who pays for the scaffold to come back.
6. What the exclusions are
Every quote has them. The useful ones are written down; the expensive ones are the ones nobody mentioned.
The cheapest way to compare two quotes is to make both of them describe the same work.