Accidentally put diesel fuel into my gas car, how much does it cost to fix?

My cousin who just has a license accidentally put diesel into my car and drove it for 2 miles before got it towed to a mechanic.

I was quoted for $2.6k. $1.9k for remove and replace fuel pump, $350 to remove and replace spark plugs plus diagnostic.

is it that much or they are overcharging me?