"UNAIDS estimates that the total global resources needed for HIV/AIDS for the period 2009 to 2013 is almost $200 billion to achieve universal access by 2010, and $140 billion for a slower scale-up to achieve universal access by 2015.83
"The UNAIDS estimates for harm reduction assume 60% coverage for needle and syringe programmes and 40% for opioid substitution therapy.84 These estimates are based on the resources needed for prevention-related activities in order to reach 6.2 million people who inject drugs by 2010 in 132 lower and middle income countries. UNAIDS assumes the cost of opioid substitution therapy using methadone to be between $363 and $1,057 per person per year (which is higher than other estimates in Table 4) and the costs of needle and syringe programmes to be $10 per person per year (lower than other estimates in Table 3).
"Using these figures, UNAIDS estimates that the resources needed for harm reduction are $2.13 billion in 2009 and $3.2 billion in 2010, an average of $170 and $256 respectively per injector per year. Additional resources will be required for antiretroviral treatment, care and support."85

Source

"Three cents a day is not enough: Resourcing HIV-related Harm Reduction on a global basis," International Harm Reduction Association: London, United Kingdom: 2010.