Why did building the stadium cripple Arsenal (and Derby, Sunderland, Southampton etc) financially for more than a decade then?
And why have we been in austerity mode for the last 7 years (zero net transfer spend since summer 2007)?
Part of what we've been doing is establishing a sustainable Ajax/Dortmund/Porto 'buy-low sell-high' model where we are able to compete without spending any money. Why would we throw that away and go all spendthrift on the eve of embarking on the biggest capital project in our entire history? It would be like just scraping up to your deposit level for buying a house, then going out and blowing a big chunk of it on a speedboat before your mortgage has come through.
Building the stadium didn't cripple Arsenal at all. They've been rolling in money for years - making huge profits ever since they moved into the Emirates. Their lack of spending has largely been down to Wenger's stubbornness, from what I can tell.
But let's, just for the sake of it, assume that you were right. A quick look at the differences between the two clubs' circumstances at the commencement of their respective construction projects:
It might surprise you to know that Spurs, without Champions League money, are considerably richer now than Arsenal, with Champions League money, were in 2004. Arsenal's turnover back then was £138.4m. For the past financial year, Spurs' turnover will likely be in the region of £190m. So Spurs will be in a better position to service their debt without it affecting the club's normal operations.
Secondly, interest rates have never been lower. Certainly, they are far lower now than they were when Arsenal went to the banks. Spurs also have the advantage, ironically enough, of Arsenal having proved that a responsibly managed English club can take on a major stadium project and make it hugely profitable.
Except for Archway, Spurs owns all the property they need and they are debt free. Arsenal had to spend £60m on a new waste and recycling plant for Islington. Where Arsenal did have the advantage, of course, was the ability to redevelop and sell Highbury - a much bigger and more profitable development than our enabling development will be. But, in the short term, it did mean that their debt rose massively until the new properties were sold.
Lastly, it is universally acknowledged that Arsenal hugely undersold themselves when agreeing their naming rights deal with Emirates. Not just the naming rights, in fact, but also the shirt sponsorship. I think we all know enough about Daniel Levy by now to know that there is zero chance that he will make the same mistake.
The other clubs (that you mention as having had stadium finance issues) are irrelevant. We are following the Arsenal stadium model.
As to your next claim - that we have been in austerity mode for the past 7 years - where do you get that idea? It's true that we have earned almost as much from player trading as we have spent over the past four years but that's because wages rose dramatically in 2010. By £30m, in fact. Curiously enough, £30 million is more or less the amount that we had become accustomed to spending, net, on transfers every year. So you see, we were spending every penny that we could on the team. The only difference is that it went towards player wages rather than player transfers. There was nothing being held back for the stadium.
And no, ours is not the Porto or Ajax model. Our aim is to balance the books through normal operations. Not through player trading. We sell only when we do not wish to keep a player or when a player no longer wishes to stay with us.