Matisyahu

Hi guys, I'm new here...

got a newb question, so please be easy on me.
Let's say I have a source for buying 404 traffic for $3 or less per 1000.
Now, on Buy404s.com they say they're paying $4 per 1000 404 hits...

so, what's keeping me from buying for $3 per 1000, sending that traffic to Buy404s.com and making $1 per 1000 for traffic that isn't even mine?
I mean, there has to be a catch...