I don’t think there is anything wrong with a frum Jew eating Goyish brands (I don’t think a frum Jew should be “digging into” anything). However, there is a halachah that one should buy from Jews before buying from Goyim. That doesn’t mean that if a Jew is selling it at three times the price you have to buy it from him, or you have to buy a brand that you don’t like just because it’s Jewish, but that you’re looking to support Jews before you look to support Goyim.
The way I look at it, if there is a Jewish product that’s more expensive than the Goyish, or there is a Jewish product that you like less than the Goyish version: what would you do if your own brother was selling it? If the difference between the Jewish and Goyish brand is small enough that you would buy the brand you like less if your brother was selling it, then you should buy the Jewish brand. If however the difference is so great that even if your brother was selling it, you would buy the other one, than you don’t have to buy the Jewish brand.