Space Tourism on the ISS
NASA recently changed a long-standing position against private citizens aboard the International Space Station (ISS). In theory, it's not supposed to just be a Space Tourist endeavor but an opportunity for commercial industry to utilize the ISS for its own science and research (pdf). NASA intends to set aside roughly 5% of its resource time aboard the ISS for paying customers. How much will it cost? Estimates range between $11K-22K per day depending on the level of support required. While that sounds cheap, it does not include the cost of getting to the ISS which should exceed $6K per kilogram.
While groundbreaking for NASA, tourists have been aboard the ISS before. Space Adventures worked with the Russian Space Agency early in the 21st century and sent 7 tourists on 8 flights into space at cost around $20M each. The tourists rode in a vacant seat aboard the resupply Soyuz ships and got to mill around the ISS during the crew changeover periods.