The only recent shortage I've seen was at Walmart, on Walmart-brand bread (Good Brand? Great Brand? Good for you brand? something like that...)
Anyway they have their own brand of whole wheat, multigrain, flaxseed breads etc. They are priced at 11.90 a loaf, compared to about 20 pesos for Fargos "Tipo Casero" multigrain loaf, and about 25-27 pesos for the Orowheat bread (that we used to buy when it was expensive at 13(!) pesos). I have no problem buying it during early weekdays, in fact now I just buy 4 loaves at a time and put in the freezer. On the weekend it looks like everyone raids the shelves, and the Orowheat/Fargo only gets touched when the walmart brand is no longer an option. It's pretty good bread I have to say, although the flaxseed loaf tends to fall apart.
Just now I was at the chino because I forgot to pick up milk the other day at Walmart. Last time I bought it at walmart it was 7.50 a litre -- perhaps it's gone up by now, but in the chino the litre of skimmed milk in a carton was 8.50, and that new DHA one was 9.50!