I have a feeling that when he leaves the owners will start sanctioning spending on par with the other big clubs, but only after a period similar to United's when SAF left.
I'm pretty sure AW has always had quite a large say on who comes and goes. Of course, things were easier when Dein was around - he brought in Vieira most notably, but was also instrumental with all the other great signings such as Anelka, Henry, etc. I get the feeling that AW is purposefully shrewd in the market. He got some of the best players at the time for next to nothing (Toure was something like £500k?), and hasn't woken up to the fact that players are now way overpriced thanks to clubs like Chelsea (who started it all in 2004) and that you now have to pay through the nose to get in quality. He's still trying to find that "diamond in the rough" that he can mould into the next Henry. Again, another sign of how he's behind: clubs buy ready-made stars because modern football demands instant success. Yes, we've signed Sanchez and Özil, but a team seriously challenging for the title needs World Class in every position, not just two.
I'm not so sure the club will allow the new guy to just start spending, either, as everything still has to go through Gazidis, who I think is also part of the transfer problem. We need a takeover by someone like Usmanov who will throw money at the problem. As much as I've hated the spending by Chelsea, City, Liverpool, United and Spurs, I've finally just given up and realised that it's the only way to keep up with the pack. Modern football is about money - lots of it. Sure, the fact that AW has kept us in the top 4 with spending less than half of what other clubs have is admirable, but it's time to aim a bit higher.