That's quite right - it depends on the company, and with some the station is the place yet others you can purchase and plan reliably. The problem with most non-Mexico residents is they do not have any way of evaluating which company, so members' experiences posted on FT make a difference (e.g. ETN, a top notch company).
Originally Posted by
globetrots
"Planning a Mexican bus trip via bus line web pages is almost a complete waste of time. Until you are at the bus terminal and talking to an agent you can't accurately plan anything... "
This depends greatly on the bus line. With ETN you can purchase in advance with a credit card, pick your seat, print out your boarding pass, and you're good to go. Easier than a flight. Others....not so much. Some you can buy at a convenience store or kiosk though if you can fumble through in Spanish. Like Oxo stores for Primera Plus.