If you're not Real, Barca, United and maybe Bayern, you're a feeder club. Or potentially a feeder club.
PSG might not fit in that profile, as they've got stupid money, but if Real came a calling and said we want X player, they're probably going to get them. Chelsea to an extent aren't, because they're winning the premiership and have shown they'll spend what it takes to keep players in wages. However, once again, if Real or Barca came and said, we want X player, odds are they're making the move.
To think that Arsenal isn't above that (with the current manager and owners) is just not looking at facts. Sure, they're able to go out and buy a lot of good players, and they're able to pick up players from a lot of different places. However, at it's core, they're still going to be funneling players to Real or Barca if they want them. That's the reality of football. It just so happens that they haven't had anyone good enough (though I think you might see one or two in the next summer or so)