An MBA is a question of timing: get it wrong and you'll find yourself spending 40k+ on two years out of the market when pay is peaking; even worse you may then find it impossible to get back in due to a glut of recently redundant experienced analysts.
Equally, however, if you're determined to do an MBA and you put it off for too long waiting for optimal market conditions, you'll find you're passed it.
Age discrimination laws mean banks will never admit to turning their noses up at fresh MBAs aged 33+, but this is the reality. Hiring a recent MBA aged 40+ is totally unheard of.
"As a general rule, banks hire MBAs into their associate programmes when they are in their high 20s and low 30s," says Julian Birkinshaw, deputy dean at the London Business School.
"There isn't an age at which it's too old to do an MBA, but there is a point at which big name recruiters will stop being very interested in you," Birkinshaw adds. "They will never say this, but the reality is that organizations like banks are looking for people who will give them the best years of their lives and who have the potential to become managing directors before the age of 40."
Banks' MBA recruiters were unwilling to talk about the age profile of their MBA hires on the record. Off the record, however, one said they have some "pretty experienced" people applying to the associate programme and that they'd hire anyone (regardless of age) who can demonstrate the, "commitment and tenacity to work 24/7."
Too old to sacrifice everything to an associate programme?
Herein lies the problem. By the time you reach 35+, the perception - rightly or wrongly - is that you've got better things to do than spending 20 hours a day in the office.
"If you have a family, it will be hard to demonstrate that you're prepared to make the commitment," added the head of MBA recruitment.
Equally, as you get older there will be doubts as to your willingness to be managed by a 25 year old.
"In terms of their ranking within the organisation, a first year associate is only three or four years in," said another MBA recruiter. "Will a 35 year old really feel comfortable with that position?"
If you're in your mid-30s and are only now thinking of doing an MBA, there are other options.
One is to apply to IMD in Switzerland, where the MBA class contains numerous 34 year olds (unlike Harvard, which now accepts people with only 2-3 years' work experience and where only 1.2% of the class of 2010 is aged 31+.).
Another is to opt for a part time executive MBA of the kind favoured by most 30 year olds with established careers.
But while both these options will stand you in good stead for a career in industry or consulting, don't expect either to do you any favours when it comes to getting ahead in investment banking.
Only 6% of IMD's class of 2008 went into financial services careers, and pure investment banks like Goldman Sachs and Morgan Stanley are noticeably absent from their list of hirers.
Meanwhile Birkinshaw says banks aren't overly interested in hiring executive MBA students at LBS who are trying to break in from another industry, or those who are using the course to move into a revenue generating position.
"The difficult message that we have to communicate to our EMBA students is that if they graduate in their mid-30s it will be difficult for them to get into investment banking," he says. "It will also be difficult for them to transition from the middle to the front office.
"If you want to do that, you will really need to do it following a full time MBA in your late 20s."