The tile contractor I work with is from Ensenada and I have weighed this out with him on occasion for my own jobs.
It never really penciled out. If cheap stock tiles are suitable, porcelain is great and not much savings could be had by buying the more fragile ceramic or clay from Mexico.Considering the trip, it is a lost cause. You can get ceramic tiles very cheaply here.
If you want custom tiles then I think Mexico is too time consuming and risky compared to going shopping Miramar Road or to the tile stores around the city.
The only thing I can see is getting a few folk art type tiles to use as accents, if that is something interesting, I would probably look for them online.
