Neil Lennon's side have shown success remains a priceless commodity

There are no simple comparisons, and Malaga have endured traumatic spells since Sheikh Adbullah Al-Thani, a Qatari billionaire, bought a majority shareholding in the club in June 2010. The original intention was to run it prudently, but the combination of a disappointing season and the threat of relegation prompted a more radical view. Manuel Pelligrini was brought in as coach, then the summer of 2011 was marked by a splurge on players, with the likes of Ruud van Nistelrooy, Santi Cazorla, Joaquin and Jeremy Toulalan all arriving. The summer transfer spend was in the region of £50m, and Malaga were rewarded with qualification for the Champions League.

Last summer was about downsizing, at least in terms of largesse. Van Nistelrooy retired and Cazorla was sold – at a slight loss – to Arsenal. Even so, the squad is still well-stocked, since Julio Baptista, once of Arsenal and Real Madrid, Javier Saviola, the Argentine internationalist, and promising young Spanish players, Isco and Ignacio Camacho, remain. The club's owners still envisage that they can become the third force in Spanish football, and Malaga will still be able to spend at a level that Celtic, while they remain in the Scottish game, cannot match. But then Neil Lennon's side has been built by different methods, and football is broad enough to be able to accommodate contrasts.

Paris St-Germain have been less reserved. Only Manchester City could compete so blithely in the transfer market as the French club, who could spend £35m on Thiago Silva, £22m on Ezequiel Lavezzi, £17m on Zlatan Ibrahimovic and £35m on Javier Pastore during the past 18 months. Even the coach is an elite figure, since Carlo Ancelotti won the Champions League as a player and as a manager, but the wealth of the Qatar Sports Investment group that owns the Parisian club brings with it impatience and restlessness.

Ancelotti has to regularly answer questions on his future, despite PSG still being in contention to win their first title in 19 years, because the team has not left the rest of their domestic rivals behind. The club's owners are said to want to bring Jose Mourinho, Pep Guardiola or Arsene Wenger to Paris, and even the position of Leonardo, the sporting director, is said to be under threat.

PSG have invested millions in trying to immediately become one of the continent's stellar sides. That kind of ambition can be accommodated by the riches of the owners – who in turn believe the money they spend will establish Qatar as a dynamic, powerful state – but it can also generate a lack of continuity. The fundamental aspects of a club, the youth development and coaching ethos, is sacrificed when the focus is solely on enabling the first team to be competitive at the highest level.

PSG have been linked with moves for David Beckham and Cristiano Ronaldo, with the former representing the kind of marketing clout the owners would like to wield, and the latter, in all of his glamour, accomplishment and status, is the embodiment of their aspirations. It is unlikely that these foreign owners would suddenly pull out of these projects, although rumours abounded for a time last year that Malaga were on the market before Al-Thani reiterated their commitment, but they are in many ways the antithesis of Celtic's approach.

It is by necessity that the Scottish champions have established a coherent and self-sustaining football policy, one that identifies potential, buys players for modest fees, develops them, then sells on for a profit. Barcelona executives were moved by the emotional intensity of the home fans during their visit to Celtic Park last month, but the Scottish market restricts the club's financial might, at least on a European scale.

Yet, by having the foresight to invest in scouting and youth development, and allowing Neil Lennon to develop as a manager, Celtic are competing on the same stage as more cash-rich clubs.