I found Bob's Red Mill Gluten Free All Purpose Baking Flour at $5/5lb bag. The price is very reasonable! on the top, it says, "Cakes, cookies, waffles...." 1:1 ratio with two different recipes on the back for waffles, and etc. It does say that some recipes will need xantham Gum (which i don't have any lying around the house), so I made my lemon bars as per my usual recipe (which I get really good feedback about), and let it cool completely.
VERDICT: It probably could have used some x-gum, but then it's not REALLY 1:1! The crust was grainy and it fell apart. The curd on top was still really good, so I would suggest using this for things that don't need to be held together, or that don't require a good crunch, like curd, or gravies and sauces. I will have to try a cake recipe to see how it works!