Any ideas on the easiest and most reasonable ($) way to get from here to there?
It seems complicated , however , knowing the "Forum " , I'm sure there are lots of ideas out there!

I did this in partial reverse...JFK to CDG, take TGV from Montparnasse to Biarritz (5 hours). Could also be that a TGV from CDG is possible now. Wasn't about four years ao. Looking for hotel, I can highly recommend a great choice in nearby Bidart, a very small beach town about 3 miles south. <b>Villa L'Arch</b>.

Why not take a connecting flight from CDG? You should be able to add it to your ticket at minimum cost. Other than that you have to take the train, about 6-1/2 hours from CDG, with prices starting around €84.

Villa L'Arche web:

http://www.villalarche.com/anglais/

Flying from JFK to Biarritz has its complications but they are worth considering. The dominant carrier to France from JFK is the AirFrance/Delta pool. AF does fly Paris-Biarritz but the direct flights are from Orly, all the way across town from your arrival at Charles de Gaulle (there is a long shuttle service.) An alternative is to specify your route as JFK-CdG-Marseille-Biarritz. Air France will sell that trip for nearly the same as if you got off in Paris. Lyon can be substituted for Marseille. www.airfrance.com To find these routes you have to specify the connecting city, such as Marseille. On the opening page you pick round trip and the next page lets you go to multi-destination tickets (a dumb design.)
easyJet flies direct from Charles de Gaulle but it doesn't connect to other airlines. www.easyjet.com RyanAir flies direct from Dublin but also does not connect (which means you go through immigration and customs and then have to check in your luggage and go back through security.) www.ryanair.com
Tools to explore other options:
www.skyscanner.com for budget carriers.
http://en.biarritz.aeroport.fr/ to see what flies there from where.
www.itasoftware.com for information on international carriers although it does not sell tickets.