The lifetime cost of treating an HIV positive person was estimated in 1997 to be $195,188.

Source

Holtgrave, DR, Pinkerton, SD. "Updates of Cost of Illness and Quality of Life Estimates for Use in Economic Evaluations of HIV Prevention Programs." Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology, Vol. 16, pp. 54-62 (1997).
http://www.ncbi.nlm.nih.gov/p…