Ferguson says the only way he would spend a massive amount of money for one player would be to re-sign Ronaldo.
The United boss says the inflated price of players in the modern transfer market does not provide a reflection of their true value and that he would not spend over the odds in the close season.
Disquiet has grown from some United supporters who claim the controversial Glazer family who own the club have denied their manager funds needed to remain at the height of English football.
But Ferguson says he has been sufficiently backed with funds in the boardroom, pointing to the combined £20million shelled out for Chris Smalling, Javier Hernandez and Mame Biram Diouf ahead of next season.
"It's not my way to buy a player for £60million," said Ferguson. "There's no point pursuing that argument. I would not contemplate signing a player for that amount."
When asked if he would pay £60million for Barcelona's Lionel Messi, he answered: "No. I'd pay £60million to take Cristiano Ronaldo back. But that's it.
"The proof of the pudding is in the eating, isn't it? They have given me £20million for three players already. And any time I've asked for a Berbatov they've supported it. There's no criticism from me because no criticism can be justified."
The comments suggest Ferguson is unlikely to spend massively in the summer compared to the likes of Real Madrid and local rivals Manchester City, who have previously invested heavily in their squads.
The Old Trafford chief has instead insisted he will stick to his policy of investing in younger players who can develop under his stewardship.
And Ferguson added that the way the huge sums incur added costs means he will be keep spending at a premium.
"The transfer market is inflated," he said. "Agents get in touch to say this player will take a drop in wages from £10million to £8million. Very good of them! Crikey!
"You could bring in a player for £40million but then there's salary and tax. You are then talking £80million. We like to get players who will develop at the club because the long-term view has to be important.
"People were worried last summer when we took Michael Owen (on a free transfer) and didn't spend £50million on some other player, but I wasn't prepared to do that."