I asked for an itemized breakdown and he just didnt answer back - got more quotes lined up for next week
That's a good indication that they were trying to use you for a big payday.
Get as many quotes as you can in, within a reasonable time frame.
In the meantime you can take a look, and run the cables, Install boxes and receptacles. This way you are just paying for them to do the connections and inspect your work.
Or if the relief of the price being significantly lower, pay them to do it all.