People's perception of 'game changing' seems to stretch only as far as a bigger transfer and wage budget (which it could be argued are larger than they would have been without the Prince). I'd suggest that it goes further than that.
It was clear before the Prince's involvement that we were in a sorry state financially. We still had large debts (subsequently written off by McCabe after the Prince stepped in), a large wage bill and worsening losses. His involvement has meant that it's no longer a NECESSITY for us to sell our best players annually in order to recoup some of those losses. Please note the emphasis, it's important, as it doesn't mean we don't still sell players, it just means we don't have to. We have more power to resist offers for our players, but ultimately as we know player power still reigns supreme. However, we are in a position to get more money for our talent - Jamie Murphy and Harry Maguire, while not perfect deals by any means, showed a glimpse of some fight (we knocked back several bids) and we received decent deals for them. There is evidence to suggest that much of that money was put back into the first team, although it was largely wasted until just over a year ago...
I think the mis-interpretation of the investment, which can largely be attributed to silly phrases spouted by McCabe and Phipps ("think Liverpool"), is the issue and not the investment itself. I for one appreciate it and welcome any further investment the Prince can source for us. That said, I think there is a decent amount of money already available to Wilder, who I believe is currently playing his cards close to his chest. I wouldn't be surprised to see a couple of big (relatively) signings this window and our levels of spending increasing substantially over the next couple of years at a sensible rate.