West Ham United co-chairman David Sullivan admits they need to step up their transfer plans after winning the Olympic stadium tenancy.
West Ham's ruling duo of Sullivan and David Gold broke the club record by shelling out £10.75m for winger Matt Jarvis last August.
Joint-chairman Sullivan said: "We realise we have to buy better, spend more money. It's a gradual process.
"But if the king of Saudi Arabia wants to come along we'll step aside.
"Or if another person wants to join us, the three of us will put the money in. It'll take time to build the team.
"Hands on hearts it is very hard to compete with the likes of Chelsea and Manchester City, who have external benefactors.
"It is hard to compete with the guy who owns Abu Dhabi and doesn't pay any tax. It is difficult to compete with Roman Abramovich, who owns half of Russia.
"Manchester United is a very special club. It is hard to match those three but over time we hope to close the gap. Our ambition is still to finish third or fourth in the table.
"We put £32m in last year. As David Gold says though 'I have 150 shops not 150 oil wells'.
"I didn't earn £16m last year, so I am now spending my savings."