Boss Sir Alex Ferguson wants to strengthen his side having missed out on the title to Manchester City.
The Scot has been linked with Borussia Dortmund duo Shinji Kagawa and Robert Lewandowski, and Lille's £30m rated midfielder Eden Hazard.
But he says he will spend wisely after claiming City "pay stupid money and silly salaries".
Gill claims United have the cash to compete in the transfer market.
He said: "Funds are available, without a doubt. We can still pay very well in terms of wages and transfer fees.
"City have raised the bar, but we need to move on. Financial Fair Play is just around the corner."