Is Car rental from Expedia legit ?

I'm flying over to LA for couple days, and I already have my hotel booked so I only needed a rental car for three days.

Apparently, they gave me a quote with a midsized car with unlimited mileage for $81.51. (through Enterprise)

However, when I went to enterprise and checked their prices, it was way more than what Expedia offered me.

I am very confused about this situation, and I've never rented a car before.

and possibly inform me with a good place near LAX for rental cars.