Fair point about Higuain costing less than Ozil. I guess my doubt is whether the interviews represent the truth or Wenger is set up as the fall guy for the board. If Gazidis comes out and says we don't need to spend there will be outrage but when Wenger says it it's more acceptable to the fans (at least until now). It also mirrors United a bit under Sir Alex's last years with 'no value in the market' and then when both Fergie and Gill go there's suddenly money to burn. United fans are still conflicted over who was really responsible for that approach.
However, in Arsenal's case you guys did spend a decent amount last summer, and if a new manager came in now and spent a bunch, there'd be absolutely no doubt left that Wenger was the one holding the purse strings.
Yeah, Kroenke does seem a fairly disinterested owner (from a football POV). Your point about Wenger being the more powerful of the two makes sense, and the socialistic wage structure is definitely a problem of his construction. As you say, Wenger leaving and a new ambitious manager coming in is probably the only way Arsenal fans can learn the truth about what is happening at their club.