Premier League clubs over the past decade have sold players for record fees and generated huge revenues.
Gareth Bale going to Real Madrid from Tottenham was one, Phillippe Coutinho and Luis Suarez departing Liverpool and joining Barcelona were two others, Jack Grealish and Declan Rice leaving boyhood clubs Aston Villa and West Ham for Manchester City and Arsenal respectively the most recent instances.
With these big money transfers, attempts by their clubs to find replacements or reinvest the profits gained have been largely hit or miss. So it remains interesting to see what happens this summer, with Spurs looking likely to lose Harry Kane's services for a big fee.
With just one year left on his contract, the England international finally decided to leave Tottenham, completing his move to Bayern Munich on Saturday before they lost the German Super Cup. With a new manager at the helm and a new chapter on the horizon, the need to spend wisely is more important than ever for the club.
With that in mind, let's look at where Spurs could reinvest the Kane money best.
That would be the natural first thought for the Spurs board and fans. Is there even a like-for-like Kane replacement out there and is that someone who would suit Postecoglou's system? The answer to both of those questions is a resounding no.
Spurs' attacking depth is currently Son Heung-Min and Richarlison, who saw limited game time under Antonio Conte for the most part.
Age seems to be catching up with 31-year-old South Korean and his production levels fell drastically during the 22-23 season, averaging just 0.50 goals and assists per 90 as opposed 0.90 during the 21-22 season. As good as he still is, Son has lost a fair bit of the physical prowess that made him such a terrifying forward in wide areas.
With Richarlison, he has never been given a proper go in the Spurs starting XI and with Postecoglou in the process of rebuilding the squad, this feels like the perfect chance for the former Everton man to stake his claim as a starter.
There are no doubts about Son and Richarlison's ability to finish and be the number nine presence that attacks the last line of defence. For all the ability he brought on the pitch, Kane was never one to occupy centre backs too much, instead drifting deeper and wanting to get involved in every phase of his team's movements.
Son and Richarlison bring different qualities to the table and perhaps the kind of qualities that may ultimately make them a better fit for Postecoglou at Spurs, moving them into the centre forward role will open up space for investment in wide areas, which is one of the positions where Spurs could do with some depth in quality.
Spurs need more options on the left and right wings.
Options on the left currently include Son, Ivan perisic and newly signed Manor Solomon, who was brought in on a free transfer after spending last season on loan at Fulham.
Meanwhile options on the right after Dejan Kulusevski are suboptimal at best, though both Emerson Royal and Pedro Porro can play higher up the pitch, they are likelier to be used as fullbacks in Postecoglou's system.
A premium option on the right could be Brentford's Bryan Mbeumo but he'll cost big money given his importance to the Bees, and now even more so with Ivan Toney's suspension.
Rennes' Belgian winger, Jeremy Doku, could fit the bill nicely.
The 21-year-old was brilliant for Bruno Genesio's side in the second half of last season following the departure of Kamaldeen Sulemana. He's an exciting dynamic winger blessed with pace and trickery.
Six goals and two assists last season underline his lack of output from open-play but Doku is electric and a fun player to watch because of his ability to dribble past people in bursts.
There is room for improvement in his defensive work and end product, but the raw quality already present within him suggests that with the right coach, he could go far. Postecoglou could be that man.
Another area that may still need addressing is defence.
Prior to this summer you had to go back to the summer of 2013 to find the last time Spurs signed a left-sided centre-back on a permanent, and that was Jan Vertonghen. These days, Ben Davies can be found starting in that role.
Clement Lenglet was brought in last season on loan as a stop-gap option, but has since gone back to Barcelona without much success in England.
Therefore, a left-sided centre-back has to be a top priority, one who can play in a possession-based side, especially in a back four, and help progress the ball from the back.
As of right now, Davies is the only option who can play in that role and while he's done well enough in the past couple of seasons, an upgrade is essential to elevate the level of quality in the squad.
Tottenham have signed Micky Van de Ven and have been linked with Bayer Leverkusen's Edmond Tapsoba, but there is another name that should be mentioned.
Enter Arthur Theate.
Rennes centre back Theate has been quietly developing a reputation as a highly skilled ball-playing defender.
The 22-year-old has already played in Serie A previously with Bologna and now has a season's worth of experience in the physical environment of Ligue 1 as well. He's very comfortable in possession of the ball and has the confidence to affect ball progression either through his exceptional passing or carrying.
Defensively there are some question marks, but there is no doubting the Belgian's suitability for a ball-dominant side and alongside Cristian Romero, the two could form a very mobile and aggressive defensive partnership.
Another potential worry for Postecoglou is that, should Pierre Emile-Hojberg leave, Spurs would be light in a key area on the pitch, with no deeper-lying number six type midfielder.
The Australian seems to prefer a double pivot so far at Spurs with Bissouma being the more mobile player of the pair, so a more disciplined midfielder who can handle the defensive work and also contribute meaningfully to ball progression is key.
In that Venn diagram, the options that are good and also financially viable for Spurs are limited.
Romeo Lavia of Southampton could be an excellent fit, however, with bigger fish like Arsenal and Liverpool also looking at him, it is unlikely that Spurs will be able to secure his services.
It makes more sense to go after someone like Fiorentina's Sofyan Amrabat who fits the bill in terms of the requirements that Postecoglou would have from a number six. With his ability to be secure on the ball, aid ball progression and hold his own defensively, Amrabat ticks a lot of boxes.
Amrabat has been linked with Manchester United in recent weeks but with the Red Devils focused on getting a number nine for Ten Hag, this is the perfect window of opportunity for Spurs to get the Morocco international.