Just after 9/11 traffic to Mexico slowed down considerably for a few weeks or months. But 9/11 isn't a concern now regarding going to or from Mexico. If anything the new passport confusion and failure to upgrade the border cities of Ensenada and Tijuana have more to do with the lack of traffic to those cities from US citizens, but still they got thousands of visitors every week and those cities are still very busy.
When I go down to Ensenada I usually don't monger, but I do check out places like Anthony's briefly, and I believe the prices are about $100 bucks for a girl, and then you have some much smaller places I bet you can even get it for cheaper, but I'm not sure. Ensenada's bar scene just isn't as busy as TJ's so the bars can command a little bit more money for it's girls.