Its not rude. It's the facts. Even 5 years ago the $300 and under milsurps were a limited group - sks, Mosin, Enfields (sporters only, not full wood), K31, svt40... Now, the sks is literally the ONLY milsurp under $300 (unless you count sporter Enfields and carcanos).
$300usd on gun broker is not a reasonable comparison for two reasons - first is exchange rate, that's $400cad, second is the fact that they are competely separate markets. Of course, if the guns are so much cheaper on gun broker you could always buy one there and get it shipped here by IRunGuns...
I suggest you do a bit of reading on how supply and demand works. You'll be far less confused about the dynamic world of milsurp pricing once you've learned some basic economics.