It was just a few months ago that Aston Villa's most successful manager since Ron Atkinson was told he would have to sell players if he wanted to bring any in. And when he did line up a record £24m sale of James Milner, he was told he couldn't have any money to strengthen his team.
Villa owner Randy Lerner had made it clear that he would not be dragged into the world of crazy transfer fees and huge debt.
Game over: O'Neill was never allowed the sizeable funds required to capture players in Bent's price bracket
That sort of deal would be outside of our means,' said the American Lerner when asked if they would sign a £30million striker.
Yes, Villa had finished sixth three seasons in a row under the Ulsterman, but they were going to have to grow the hard way - use academy players, make shrewd, cheaper signings, get the best out of what they had at the club already.
The wage bill was already ridiculous and O'Neill had apparently reneged on his promise to sell more players after splashing out £17m in the 2009 summer transfer window on Stephen Warnock, Richard Dunne and James Collins.
Unfair deal: O'Neill's relationship with Lerner broke down after the manager failed to sell players to raise funds
Lerner was not impressed by O'Neill's failure to recoup the funds, their relationship broke down and big-money signings seemed a million miles away. Oh, how things change.
O'Neill, of course, left on the eve of the season and Villa are now only outside the relegation zone on goal difference. But Bent, a target for O'Neill the previous summer before he went to Sunderland, is finally getting his move to Villa Park - for an incredible £24m.
That - along with the signing of Cameroon midfielder Jean Makoun from Lyon for £7m - is quite a way for Lerner to back his manager, Gerard Houllier, especially considering the Frenchman's dismal record since he arrived in September.
Villa have managed just 12 points from Houllier's past 16 Premier League games but it seems he is safe in his job. Few would argue that £24m for a striker who is out of form and has continually proved himself to be below international class is extortionate.
But few could argue either that Villa don't need Bent. They have scored a disappointing 24 goals this season in the league - only four teams have fewer - and there is a genuine worry that they do not have the strikers to keep them in the division.
AND THEY OWE SOMUCH TO JIMMY HILL. As Darren Bent negotiates a bumper new salary package atAston Villa he might care to spare a thought for the men who made such riches possible.Today marks the 50th anniversary of the abolition of football's maximum wage.
On January 18, 1961, players'union leader Jimmy Hill succeeded in having footballers' £20-a-week salary cap scrapped.
'Hill's hour of triumph,' was howone newspaper described theformer Fulham wing half's role.
'League agree to end the soccer slave contract,' screamed another.
Gabriel Agbonlahor and John Carew have not scored in the league this season, Emile Heskey is injury-prone and past his best, while Nathan Delfouneso is too inexperienced to rely on. Bent is a fantastic addition with plenty of years ahead of him at 26 and he will score crucial goals for Villa, even if he has only one league goal in his past eight outings for Sunderland.
He should get plenty of opportunities too because, for all their faults this season, Villa possess some of the best wingers and deliverers of set-pieces in the Premier League.
Marc Albrighton on the right and Stewart Downing on the left have been revelations this season and Ashley Young - assuming that Houllier's promise that he will not be sold holds good - should land enough crosses on Bent's head for the goals to start flying in again.
The £24m for Bent is being largely covered by cash from the sale of Milner to Manchester City in the summer. And there is more room for manoeuvre in the wage department with Steve Sidwell's £45,000-a-week salary off the books following his move to Fulham.
There is an argument that if O'Neill had just played the game with Lerner all along and recouped the money he was asked, the American would have been giving him rather than Houllier this backing now.
You imagine Villa's players and fans wish O'Neill had played the game, too. Houllier is unpopular with key members of the dressing room, something which almost led to Brad Friedel's departure in a swap deal with Manchester City for Shay Given.
The American has been a fantastic servant for Villa and clocked up his 250th consecutive league start against Birmingham on Sunday, but his sour relationship with Houllier dates back to Friedel being ignored by the Frenchman when they were both at Liverpool.
A deal with City could still happen in the summer. Another player Houllier does not get on with is Carew. The Norway striker scored 17 goals for O'Neill last season but has barely figured this term and only returned to the team at Birmingham after a month of being frozen out.
What next? Niall Quinn (left) and Sunderland owner Ellis Short (right) are losing their top striker
With Bent arriving, Houllier no longer has to worry about winning over the man he sold when he was in charge at Lyon. In Bent, Makoun and on-loan Kyle Walker from Tottenham, Houllier would argue he can finally start building his own team.
Jamaica striker Omar Cummings could also be joining on loan from Major League Soccer side Colorado Rapids.
If Houllier can rebuild successfully, he might finally start to win over the disillusioned fans whom he upset so much during the 3-0 defeat at Liverpool, when he seemed more interested in lapping up the applause from the Kop than sorting out his own team.
There were 10,000 empty seats for Villa's last home game against Sunderland and there is a lot of work for Houllier to do on and off the pitch. He and Lerner had better hope he gets it all done before it's too late. Steve Bruce reeling as Sunderland's star striker Darren Bent jumps shipAston Villa weigh up loan move for Cummings after striker impressesAll the latest Aston Villa news, features and opinionAll the latest Sunderland news, features and opinion
Explore more:People: Emile Heskey, John Carew, Martin O'Neill, Shay Given, Ashley Young, Jimmy Hill, Stewart Downing, Gerard Houllier, Gabriel Agbonlahor, Darren Bent, Richard Dunne Places: Liverpool, Lyon, Birmingham, Jamaica, Norway, Cameroon