The Dutch side eliminated two continental giants en route to the Champions League semis, but how does their squad value compare to Europe's big guns?
Ajax this week will take on Tottenham in their first Champions League semi-final for 22 years, with a place in their first final since 1996 a real possibility.
There are endless stats that emphasise how great an achievement it is for the Dutch side, who hadn't reached the knockout rounds of the competition since 2005-06 before this season, but few stress the point stronger than the cost of Erik ten Hag's squad.
Using initial transfer fees only, Goal has calculated the total cost of Ajax’s 25-man Champions League squad before doing the same for the other biggest sides in this season’s competition, including the likes of Real Madrid, Juventus and Manchester United.
GettyPSG | €718m
With PSG possessing the two most expensive footballers of all time, it's no shock to see them at the top of this list.
Below Neymar (€222 million) and Kylian Mbappe (€145m), the likes of Edinson Cavani (€64m), Thiago Silva (€42m) and Leandro Paredes (€40m) help this 25-man squad rack up an incredible initial cost of €718m (£621m/$805m).
The French outfit do have the most youth products in their 25-man squad of any team on this list, with Alphonse Areola, Sebastien Cibois, Presnel Kimpembe, Christopher Nkunku and Adrien Rabiot all having come through the ranks at the Parc de Princes.
However, despite a spend of €1 billion coming on top of that since Qatar Sports Investments purchased the club in 2012, three successive last 16 exits mean PSG are nowhere near their dream of winning the Champions League.
AdvertisementGettyManchester City | €682m
Manchester City's consistency in spending sees them come second in this list, with 12 of their 25-man squad commanding fees of €35 million or more.
That takes the total cost of their squad up to a healthy €682m (£590m/$764m), with fringe player Riyad Mahrez the most expensive purchase (excluding add-ons) after his €69m move from Leicester City last summer.
Their defence is the most expensive area, with their most common back four in the Champions League this season costing a combined €187m.
However, even all that money could not stop them leaking three goals at home in the second leg of this season's quarter-final tie against Tottenham.
GettyManchester United | €661m
Manchester United's comeback against PSG sparked the potential of a story for the football romantics, with club legend Ole Gunnar Solskjaer having the chance to replicate his heroics in 1999 as a player by guiding them to the Champions League title as a manager.
But the romance of that story – before it was destroyed by Lionel Messi's Barcelona in the quarter-finals – was not so dreamy once you analysed the figures.
The club's current crop of players have cost an incredible total of €661 million (£572.5m/$740.8m) – €189.9m of that on Paul Pogba and Romelu Lukaku alone – despite United having featured in the Champions League knockout stages just once in the last four years.
With €160.6m splashed on players who have played less than half of their games in Europe this term, it's clear the 2007-08 winners will have to spend more effectively if they want to rediscover past glories.
GettyLiverpool | €594m
After Loris Karius' error-plagued performance in last season's Champions League final, it was no surprise that Liverpool splashed out €75 million on goalkeeper Alisson in the summer.
Add his arrival to Virgil van Dijk's last January, and you have a €161.5m defensive duo – albeit, an important and necessary pair that Jurgen Klopp needed to purchase.
The squad he has built has certainly come at some price, with the recent midfield additions of Naby Keita (€61m) and Fabinho (€46m) taking the total cost of Liverpool's Champions League squad up to a whopping €593.5m (£514.75m/$668.15m).
But Klopp has addressed the areas that needed improvement and, if the money spent can help the Reds go one better than last year – both in the Premier League and in Europe – it will certainly be worth it.