samgalz is right. as consumers, we choose & compare prices.
to me, their prices are all about the some just a few hundred minor differences between contractors.
of course ID firms will definately be more expensive.
the most impt whether you like & feel comfortable with the contractor???
and definately the cheapest is not a good idea, they will cut alot of necessary things like the bonding agent and all.
i was very comfortable with mine, maybe because she was a female.