But Palacios is expected to move to White Hart Lane once Tottenham have met Wigan's demands on how the fee should be paid.
"It's a wonderful piece of business in terms of what we bought him for and what we're selling him for," Bruce said.
"But it is like losing my right arm because where do I go and find another player like Palacios?
"It's an unbelievable success story for Palacios because he was still in Honduras 18 months ago.
"We all knows that Spurs are one of the biggest clubs and can blow us out of the water in terms of what they can offer contract wise."
Palacios only arrived in England in August 2007 when he was invited for a trial at Arsenal. He joined Birmingham, managed by Bruce at the time, on loan from Olimpia before following Bruce to Wigan 12 months ago.
His move will smash the Wigan record transfer fee which is the £6 million received from Everton for Leighton Baines in August 2007.
Wigan will welcome Hugo Rodallega, the Colombia forward, to the JJB Stadium on Monday after he was granted a work permit.
Rodallega joins for a fee of £4.5 million from Mexican club Necaxa.