You are partially right sire. It's not illegal to sell/buy them, but a PAL/RPAL isn't required either. Simply think of starter pistols as a firearm shaped bear-banger. Simple as that. Yes, they are cast out of cheap pot-metals so they will not withstand the pressure of a loaded cartridge. They are specifically made to only "physically fit" and "fire" blank cartridges. The barrels are partially obstructed to only let gases and fire out. It's impossible to drill out the obstruction unless you have a diamond bit. Starter pistols are cast out of cheap pot-metals, but the obstruction is of hardened steel. Mags are shorter in length (not height) than those of a real pistol so it's impossible to fit a loaded cartridge and insert the mag. The projectile will stick out of the mag, and mag can't be inserted. These are just some examples of how blank manufacturers meet standards to legally sell blank pistols without a PAL/RPAL needed. The only restriction is of age, 18+. The only thing criminal is if a blank is used to scare or loot a person by pretending it to be a real pistol, which apparently could be done with anything; a kitchen knife or a baseball bat, lol. It's the intent. Canadian laws are mostly based on intent! For as long as blanks are used for its intended purpose, which is for wild life deterrence or cinema/theatre/movie-making/entertainment, nothing is criminal!
You can find blanks all over gnpst, twnpst, even a website everything old antiques. They sell blanks replicas of Pythons, Bulldog revolvers, M92 berettas, P99 pistols, P4 pistols, etc.
The same way, I'm here to sell my 1911-model blank.