Hey bro, I know what you mean. There is a psychology to it and I think each site needs to have it's own custom join page. However, much of the sale needs to be done before the person even hits the join page.
Small example from my experience: I removed the cost of the join on my website and page
www.exploitedcollegegirls.com/ccbill and sales went down. I put the cost of the join back onto the page and sales went back to normal. I did this a few different times to make sure that it was the real reason. Sure enough, people responded or felt more compelled to whip out their credit cards when the price was visible. This is just my site experience -- yours may be completely different.