I started with various flea market rasps, than bought two Dragon rasps which are worlds better.
But I find the triangular shape and overall size doesn't work too well in some situations (fitting into small spaces in general, and trying to file flat and straight in a small space.) My use cases are shaping, beveling, and round overs on some inside curves, and finalizing the insides of lap joints.
What would be a good, small (4 to 6 inches long, less than 1 inch wide), flat, rectangular, rasp, not super fine, ideally under $50? (In general the files this small I see are extremely fine toothed.)