* Messi could have pushed his price tag up to $36 million a year.
* He scored an extraordinary 91 goals in the calendar year of 2012.
Lionel Messi may have cost himself upwards of $30 million with a "gentlemanly" approach to his latest contract extension.
The world's top soccer star, just 25 and already considered one of the greatest players ever, extended his current deal with Spanish club Barcelona earlier this week, meaning he will remain with the team until 2018.
Yet while Messi will collect an annual salary of around $30 million over the next five years, the perception in European soccer is that Barca have got him cheap.
"Whatever you pay him, it is going to be cheap," said Brazilian superstar Ronaldinho, who played with Messi for Barcelona between 2004 and 2008. "How can you say he is worth this amount or that amount? How could there be any figure at which you would say 'he is not worth it?"
Negotiations in European club soccer are often tense and drawn out affairs. Wayne Rooney of Manchester United even flirted with the possibility of joining that club's hated and big-spending rival Manchester City as his own multi-million pound dealings became fractious two years ago.
Messi and Barcelona, however, appear to have one of those sickeningly perfect marriages and the Argentinean forward's refusal to indulge in any contractual chicanery may have reduced the amount he eventually receives.
At no stage of talks did he publicly raise the possibility that he might leave. It's believed he could have pushed his price tag to Barca up to $36 million a year, but instead chose not to play hardball.
"Messi loves Barcelona and has never made it a secret,â€ a club source told Yahoo! Sports. "At no point were there any threats from his advisors or any kind of hardball approach. The discussions were courteous and the approach was gentlemanly. Could he have received more money if he had pushed things harder? Almost certainly, probably around 20 per cent more."
Barcelona recruited Messi as a 12-year-old, moving him from his home of Rosario in Argentina to the heart of Catalan country and the club's iconic Camp Nou stadium. As a youngster, Messi suffered from a growth deficiency and Barcelona's agreement to cover the costs of his treatment weighed heavily in his family's decision to up sticks and head for Spain.
With this latest contract extension there seems little chance of him ever playing for another European team, which was confirmed by Messi himself during his signing press conference.
"I am very happy at Barcelona. I have always said so," he said. "It is a great day. I don't know how I will be when I reach 31. I just go forward day by day and try to enjoy playing football here.
"As far as Europe goes, I would like to end my career at Barcelona. I don't think about playing for another team on the continent. That said, I don't rule out ending my playing career in Argentina."
(It must be noted that Messi's salary is widely reported as $14.7 million per year, not $30 million, which is because most European soccer contractual figures are both negotiated and reported on a post-tax basis.)
"With very good players it is quite easy for the agents and negotiators," said British sports marketing and publicity expert Paul Ridley. "They take things on a like-for-like basis, and there will have been a precedent set by how much a player of similar ability makes. With the truly great players it is a little harder because that bar hasn't been set."