What's the cheapest way to get to Monterrery?

I'm having surgery on November 19th with Dr. Rumbaut in Monterrey. I'm so excited I can't stand it. The thing is that I'm looking for the cheapest way to get myself to Mexico. I'm really nervous about the thought of driving over the border. I think I would have to purchase extra car insurance since my policy doesn't cover me outsides the US. Can anyone give me tips? The airfare from Houston is only 168 pp, but after taxes and buying a ticket for my dh, it comes up to 474.00$ I'd rather save the money for airfare later for fills and stuff. I'm trying to keep this as inexpensive as possible. Greyhound's website is in Spanish......I can't find another reliable bus line. I would love to fly but can't find anything reasonable. Help me please! Katie

Grey hound doesn't sound bad at all. Since yoru that close and all. How much is your surgery costing you? If you don't mind me asking. I'm postop and saving for mine. Good Luck, and keep us posted!