Uh I think just about everyone is going to get the vaccine because nobody wants to dream about getting AIDS. That's the exact reason they ARE going to get it.
Unless it costs ten thousand dollars which there is no indication it won't unless the government steps in. (edit: not tens of thousands of dollars maybe but lots of money. Cholesterol medication costs like hundreds of dollars and a pill and that is for something extremely common.)
How many people don't get the flu shot? The flu shot is free! Admittedly the chances if dying from the flu are not that high unless you are 90 years old or a baby, but most people don't think they are going to get AIDS.
A lot of people are going to just assume they won't get AIDS because the entire problem with AIDS is that everyone is totally uneducated about it! If you think "nah, I won't get AIDS" and it costs a shitload of money to get the vaccine then why would you get it?
PLUS where do they have the most AIDS? AFRICA. And where do they not have a reliable medical service? The same places in Africa that the AIDS pandemic runs wild. Good luck trying to get people who think having sex with a virgin cures AIDS (which some people do!) to take a vaccine.
They say that an ounce of prevention is worth a pound of cure and still most people don't attempt to ramify medical situations until the last possible moment or until it's too late. Most guys I know don't want to go to the doctor because they might find out there is something wrong with them. This mentality carries over into not getting vaccinated for things they have very little chance of contracting in their lifetimes. This vaccine really only acts as extra insurance for people who are already taking precautions against it. Unless it is 100% effective it will probably end up causing scenarios like "Don't worry about a condom baby we're both vaccinated" because people are stupid!