Could you put a price on a player who has been named the world's best for the past four seasons, scored a ridiculous 92 goals in 2012 and is already Barcelona's all-time record goalscorer at the age of just 25?
The CIES Football Observatory's Annual Review for 2013 has attempted to answer that question, producing its list of the 60 most valuable players as part of its yearly, authoritative look at European football.
It's no surprise to see Messi take top spot, but his estimated value is staggering, with the Football Observatory deciding the Argentina international is worth between 217-253 million euros (£184-£215m).
By comparison, Real Madrid's own goal machine Cristiano Ronaldo is valued at 'just' 102-118m euros (£87-£100m), meaning Messi is worth twice as much as his big La Liga rival - according to the Football Observatory at least.
The Barca star is also worth no less than five times as much as Tottenham's Gareth Bale, who is being linked with an £85 million move to Real Madrid but is valued in this study at between 44-51m euros (£37-£43m).
As the study's report explains: "If Lionel Messi was transferred, he would certainly break the record for the highest transfer fee ever paid. The economic value of the Argentinian superstar is close to his buyout clause: 250m euros (£213m).
"All the key parameters generally increasing the value of a player converge for Messi: top performing employer club, consistently outstanding performances, above all in terms of goals, high level of national A-team represented, attacking position, middle career age and recently extended long-term contract."
On Ronaldo, the report adds: "With only two seasons of contract remaining and aged 28, Real Madrid probably has the last opportunity to sell him at a profit. This makes his transfer more probable than that of Messi."
Bale, though, must make do with joint ninth place, behind Wayne Rooney amongst others, in the latest report which is "estimated on the basis of an exclusive econometric model."
CIES Football Observatory 2013 Annual Review's Top 10 players by value:
1. Lionel Messi (Barcelona/Argentina) 217.4-252.6m euros
2. Cristiano Ronaldo (Real Madrid/Portugal) 102.2-118.7m euros
3. Edinson Cavani (Napoli/Uruguay) 58.3-67.8m euros
4. Eden Hazard (Chelsea/Belgium) 55.5-64.5m euros
5. Sergio Aguero (Manchester City/Argentina) 48.6-56.4m euros
6. Radamel Falcao (Monaco/Colombia) 46.3-53.8m euros
7. Mario Balotelli (AC Milan/Italy) 45.5-52.9m euros
8. Wayne Rooney (Manchester United/England) 45.1-52.4m euros
9. David Silva (Manchester City/Spain) 43.5-50.5m euros
10. Gareth Bale (Tottenham/Wales) 43.5-50.5m euros