Spurs have cracked the top 4 & they've spent around £8M net in the last 5 years. Saying it'd cost £200M for us to achieve it from our current starting position is nonsense imo.
Agreed. Assuming all things being equal (which never seems to be the case in the Prem) you likely wouldn't need 200m but you'd probably need more than the 40m suggested here. Spurs (according to you) did it with 40m net on transfers and likely a good amount extra on wages too. I found figures for 10/11 which puts their wages at 91m p/a. So over five years, combining wages and transfers, that would be approx. 100m over what we spend.
Also remember Spurs were trying to break into a CL chasing pack with one less team than we would be (because Spurs themselves are now in it). That does make a difference to how hard it might be to break into the CL.
All-in-all, without some very good fortune, I think 20m extra for transfers/wages p/a (sustained increase which holds every year not just a one-off) is about right to mount a consistent challenge (assuming it is spent in a
Moyes-y way and not immediately set on fire in a RS way). (Since everyone is getting extra TV money you might adjust these figures to account for everyone having more money and therefore everyone spending more -- meaning you'd have to spend 20m extra + TV money -- but it's generally close enough.)