Most tourists to Antarctica visit the peninsula via a cruise ship. Prices vary, but shopping around you should be able to find something in the US$10,000 range for the flight and cruise. Maybe you'll find something better.
At South Pole Station we got a very few tourists, and were told they paid about US$35,000 each for the trip, PLUS there were medical requirements. I know they flew in on Kenn Borek airplanes, I think via Patriot Hills, but I don't know who made the arrangements.