SnapdragonQ
It's coffee o'clock!
I grind my most of my own GF flours. I make oat flour in my high speed blender from old fashioned oatmeal, so that is cheap. I found brown rice grinds better in the grain attachment that came with a juicer, so again, cheap.
Unless you don't have a high speed blender. I got one of those years ago, and love it, even though it was $400. The juicer I bought used from a friend, just because it was only $25, a high quality brand, and the grinder was "something that came with it." My blender can't grind the rice quite as well as the juicer. Even so, you can feel a bit of grittiness in the flour, but it disappears when baked.
I feed my SDS (sourdough starter) half oat, half rice flour. The few times I've made actual sourdough bread, I've used some sorghum and tapioca flours with. Still experimenting to get more rise, but the flavor is awesome!
I've thought about trying to mill my own flours, but I spent my kitchen set up budget on other things instead. I love my KA Mixer and my Excalibur, but gosh, a way to mill my own flours would be wonderful.
Recently I bought some large quantities of oatmeal with the hopes of making my own oat flour, but haven't done it yet.
And yeah, I'm with you...flours that sometimes feel gritty often bake up nicely (IMO) so I'm not one of those who needs a certain brand of extra fine white rice flour. I myself prefer the brown rice flours even though they are heavier. They taste better.
Half oat and half rice...interesting. Is that the ratio you started with? Or did you work in the oat flour once you had a good one going?
With all the oatmeal I have around waiting to be cut to oblivion, I could certainly start with a half and half and not cringe so much at the cost.