I recently tried some Tetenal Neofin Blau in one-shot fashion on some Efke R100 and was very pleased with the results. High acutance and resolution, tight, sharp grain. As supplied via JandC Photo it came in a box of five vials, each containing 30ml of concentrate. The concentrate makes enough for a single roll of MF or two rolls of 35mm.
The supplied data is pretty thorough but takes some careful reading to decipher. Information is supplied for agitation (continuous and 1-minute intervals), contrast indices, etc.
It's not quite as affordable as Rodinal tho'. However Neofin Blau is reportedly a standard Beutler formula, which can be readily mixed up from commonly available chemistry. Recipes alleged to produce some version of Rodinal are available but the components are rather less user friendly.