Trying,
There are other options then just behavior modification. Tell him he is going to see a psychologist, do not offer a choice in the matter, but allow him to help pick one out, one he can trust. It sounds like youre dealing with more than just your average teenage rebellion. Deborah is right, you cannot try and bribe him, all this will do is teach him that he can barter his way out of or into anything with you. Eventually you will reach a point where it will be, "Give me what I want or Im going to smoke pot/skip school/whatever". If after trying to reach your son and talking to him, allowing him to get the help he needs he still wants to act like its his world and he's going to do whatever he wants ship him off. Don't go anywhere near the private theraputic sector, odds are he'll just end up dead there. Instead I would recommend a military school, make sure you throughly check it out first and look into their track record, many allow abuse to go on but others are truly safe enviroments. There your son will find out he cant always get his way. Hope this helps.