The United boss takes travels across town on Sunday for the first derby-day clash since City came under the control of an Abu Dhabi-backed consortium that is threatening to spend limitless amounts of money on the Eastlands outfit.
"Where are they at the moment?" replied Ferguson when asked if he viewed City in a different light.
"The money is for the future. Mark Hughes must decide how it will shape his team. At this moment in time that is not the case."
"We experienced this with Chelsea," continued Ferguson.
"They spent a lot of money. It had an immediate impact because they won the title for the next two years. In their case it has worked. You can look at other examples and it hasn't."
Traditionally, January is a difficult time to sign players of proven quality, no matter how much Hughes has to spend.
"It is easier said than done," said Ferguson.
"January is not the best time to buy players, although I suppose it depends how City do in Europe."