The art of the deal is difficult to master.
To weigh up the options, consider the consequences and assess the repercussions is a delicate balancing act.
But for Tottenham's master negotiator, club chairman Daniel Levy, this week's sale of star player Luka Modric has been partially offset by a new footballing partnership with Modric's new employers, Real Madrid.
In Levy's mind this footballing friendship is quite a coup for Spurs. The La Liga giants and the north Londoners will trade coaching secrets, play pre-season friendlies and grant one another first option on loan moves.
But the extent to which the partnership will prove useful is difficult to quantify. The friendly arrangement is little more than window dressing, a neat profile boast for Spurs.
The first option on loans a similarly unnecessary tie-up. The benefits associated with trading youth team players will be little to write home about, and it's unlikely that first-team players to the quality of Nuri Sahin will be arriving at White Hart Lane any time soon.
The coaching link sounds the most promising - a unique opportunity for the respective coaching staffs to share knowledge and improve.
But who stands to gain the most from this partnership? Madrid receive Modric - for less money than he was going for last season - and a partnership which costs them nothing.
Spurs lose one of their best players - for less money than Chelsea were offering last season - and leave themselves little time to find a replacement.
A little over a week ago, Andre Villas-Boas, speaking with the knowledge of Modric's impending transfer, said Spurs "have to be able to act straight away after." With the deadline now looming large, Spurs have £33m burning a hole in their pocket and not much time to find a replacement.
And unless they have all their ducks lined up in a neat row, they're unlikely to sign all their targets.
A desperate dash looks set to ensue, with deals for Shakhtar star Willian and France international Hugo Lloris in the pipeline.
The shortage of time restricts their options, and finding a player of Modric's guile will prove challenging. With Sandro, Jake Livermore and Scott Parker they have a rigid spine, but little flexibility going forward. Creativity will be key for a side that has struggled to score so far this season.
For Madrid, Modric becomes the latest Premier League import. Over the past 15 years the Spanish side have spent more than £250m on the finest Premier League talent, from £23m on a teenage Nicolas Anelka to £80m on Manchester United's Cristiano Ronaldo.
The results have been mixed. Ronaldo, Xabi Alonso and David Beckham were all successes. Even Michael Owen was a shrewd purchase at £8m. But Arjen Robben failed to settle - an expensive flop at £24m - while Ruud van Nistelrooy and Nicolas Anelka cost a combined £34m.
But the capture of Luka Modric should be another success. The Croatian joins a formidable midfield rotation including Xabi Alonso, Sami Khedira and Lassana Diarra.
Modric should have little trouble carving out a niche in the Spanish capital. In the big games Mourinho may perfect the defensive instincts of Khedira or Diarra, but, by and large, Modric and Alonso should occupy the central midfield.
El Clasico tomorrow tonight will come too soon for the 26-year-old. A summer on the sidelines has left Modric short of fitness, and training in isolation is no preparation for the new season.
But the hangovers from such protracted transfer sagas are usually, and surprisingly, quick to be overcome. Cesc Fabregas swiftly settled into Barcelona's midfield after quitting London, while Robin van Persie started, and scored, just a week after joining Manchester United.
The relief from moving on probably has something to do with it, and after a summer of idleness, Modric can't get onto the pitch soon enough. Players are often mocked for declaring that Madrid, or Barcelona, or Manchester United is their "dream" move, but which players don't wish to play at the Bernabeu, Nou Camp or Old Trafford.
The lure of Real Madrid, and the Bernabeu, proved too great an attraction, not just for Luka Modric, but for Tottenham Hotspur as well. Links between clubs typically take a "parent-feeder" dynamic, even if the association is implicit.
But, in this case, Spurs have seemingly attached themselves to Real Madrid under the pretense of a mutually beneficial partnership, founded with each club on an equal footing. But while neither stand to gain all too much, Spurs have unquestionably latched onto Madrid, courting the glamour of the Spanish giants, rather than the other way around.
Just two seasons ago, Spurs found themselves on an equal footing with Real Madrid. A Champions League knock-out tie against the nine-times winners could have been the start of a consolidation process, cementing Tottenham's place among Europe's elite.
Unfortunately, it looks like it could be some time before Spurs find themselves in that position again.