Wolves owner Steve Morgan says manager Mick McCarthy is working to a summer transfer budget.
Wolves have barely touched the £30million investment Morgan has ring fenced as part of his takeover of the club, since swelled by the further £30million of TV money gained by winning promotion.
The 56-year-old multi-millionaire insists the fee for Doyle and others are within budget.
He said: "I wouldn't say we're pushing the boat out - the club has a budget that we will work to.
"But we're determined to bring quality to the club."