$250 an hour may be expensive. If I hired one guy $125 an hour it would probably work out to the same amount.
Installation is $250 an hour for a 2 man crew.
The dealer’s labor rate charge is $125 per man hour.
$3000 / $125 = 24 man hours. This is the total number of hours the dealer figured to do the job. Plus tax? (If the dealer is smart he added a little fudge factor to the labor hours he guesstimated to do the job.)
That’s not what the worker is being paid though. And there is a good chance there is lead man and a helper. (Lead man makes more money than the helper, usually.) The dealer has other costs than just the wages he pays the worker. FICA, workman’s comp insurance, unemployment insurance, Liability insurance, health benefits?, service van, insurance on the van, maintenance on the van, gas, tools, ect. On top of this he adds a percentage for overhead charges. He then takes that total times a percentage for profit markup.
I have no idea what the going rate is for an audio/video total install in Berkeley, CA. The dealer's price may be fair. Call around to other dealers in your area and ask what their hourly man hour rate is for the same comparable work.
If there are other audio/video dealers in your area I would compare prices. Check for independent customer reviews.
I would recommend you buy all the equipment and have it installed, setup, and calibrated, by the same dealer. Saves on finger pointing if there is a problem.
https://www.trackstreet.com/blog/map-pricing-vs-msrp-whats-the-difference.