You might be shopping at the wrong market. The only climbing prices I've seen lately are for "Atkins Friendly" items. You want to buy a box of Carbohydrates, they're cheap as anything.
That massive Farm Bill wouldn't have anything to do with the climb in prices would it? Nor laws in many areas that forbid the selling of farm products such as milk below a certain price.
I have yet to see a single store brand disappear. I buy lots of store brand products. Have for years. And haven't been unable to find them.