Well, from my limited 100-level-chemistry-plus-youtube education, he could have just bought the immediate precursors directly for pyrimethamine itself, i.e. pos

Well, from my limited 100-level-chemistry-plus-youtube education, he could have just bought the immediate precursors directly for pyrimethamine itself, i.e. possibly even 2-(p-chlorophenyl)-3-oxopentanenitrile, guanadinium chloride, and Trimethyl Orthoformate, which would make it a 3-step synthesis instead of a 17-step synthesis, so yeah, pretty easy. At the very least he could cut out ~2/3rds of those steps for a 7-step or 6-step synthesis. So cheaper by easily an order of magnitude, possibly ~$100 a batch or less. Of course, if you want FDA grade instead of technical grade your prices for everything skyrocket and your workup has to improve a bunch.