You can check the Internet and see what similar cars are going for in both states. It is probably very similar. If you buy it in CA you will have to pay sales tax and register it, then you will have to pay registration in LA and possibly fees related to transfering title into the state and maybe a use tax. It can be expensive.

The actual price of the car won’t vary by much; for a new car, you’ll be charged a destination fee for transportation from the factory to the dealership. Taxes will vary quite a bit; if you buy a car in California, you’ll pay sales tax there, and may have to pay additional taxes in Louisiana as well. But I would base the decision on something else altogether: how much stuff will you be schlepping from California to Lousiana, and does it make sense to haul it by car? Moving companies are expen$ive.

Cost of vehicles can vary not only from state to state, but from city to city, and from dealership to dealership. Sales tax varies from state to state also.