why you want to purchase it? because I think that almost every script is available on internet for free?
really ? You get top notch official support for nulled script isn't it ? I don't think vB accepts alert pay. PayPal, Credit Card and Wire Transfer are the options available for you. Or u can get it from some one else and pay them for the vBulletin license (+ possible commission) as well.
Hey, I have a licensed version of vBulletin 4.0 Classic ( Not Expired ). I bought it using credit card. If you are looking for used licence then PM me.
You'll have to see your options at www.vbulletin.com/order/ or find a used license on DP or other webmaster forums.
nulled forum script gets banned or its always risk to get it close down so no point of you working hard to get your website at top and then you see its closed down.!!! so its better to buy it. It happened with me somebody reported my website cuz it was getting so much traffic.