I didn't say 'based on transfer expenditure', and the fact that it's the big club managers that dictate that list makes it a laughable example of which manager has done the best with limited finances. Even bloody Mancini is high up on it (although admittedly only four spots above Moyes, it should be noted), and we all know he spent more than a pretty penny!

Anyone who has played Football Manager knows that while a good transfer kitty is nice, there is a massive difference in the revenue a club has when you drop from the Uniteds, the Liverpools and the Arsenals (let alone Chelsea and City) down to the clubs that actually struggle to find a way to pay for a player's wages.

The biggest surprise on that list is indeed Sam Allardyce, though. Never thought he did that well. 14th of 162 PL managers? Huh. Who knew? I will also point out the conclusion of the same writer who put together that article...

For Everton to truly compete with the Big Six they need a much bigger stadium and other sources of revenue to support the spending that is required. In a drive to balance their books and look for additional investors, Moyes and the club will have to go back to the days of a starting XI that costs around £45M and enjoy the financial benefits of weekly wages that are also at lower levels.
In the comments on his article on Moyes, he even concedes that there are definite flaws in the system he is using, such as the Rooney situation. It is a very good system for analysing points per transfer fees paid for players, but does not take into account overall financial situations at the club, nor does it even consider how much net spend was used - only total outgoing expenses.

EDIT: You mention Jose Mourinho, Carlo Ancelotti and Rafael Benitez for a second time after previously admitting yourself that you understand why they didn't go for them? C'mon, dude. Available does not mean a better candidate.

EDIT: After analysing the list a little more, once you take away the managers who have had the luxury of big money at Liverpool, United, City, Chelsea and Arsenal (I would mention Spurs, but there are no Spurs managers above Moyes, ha)...

1. Frank Clark - Nottingham Forest, early 90's, non-comparable.
2. David O'Leary - Leeds United, noted for overspending in a way that is not financially stable.
3. David Moyes - Hi!