Tips for no problems with me crossing with controlled meds -Don't carry more than 180 and don't declare them. Always buy & declare the tequila and the cigarettes ( I don't smoke tobacco) though. And buy a couple mini bottles of mescal with the worm in it - that really makes one look like a tourist.

There are plenty of farmacias that sell controlled meds, they just aren't on Revolucion or the main streets. And yes the prices are generally higher than one would expect. Doctors can also be found readily available - off the beaten paths, sometimes next to or above the farmacias. Get a script from a local doc and you can get whatever you want - just remember the script is no good out of mexico.