A fee, reported to be £600,000, was agreed over the weekend and the South Africa international, who joined the Championship club on loan last season, is settled on a three-year deal.
Palace are now expected to officially announce the move on Monday afternoon and Freedman believes that Dikgacoi represents a good investment.
The Palace boss told the Advertiser: "KG will sign on a permanent deal. He's my kind of player and I've persuaded the chairman to buy him.
"At only 26 he is only going to get better with more games and I see it as a good investment for the football club.
"He wants to come here and play and I am only interested in players who are keen to play for Crystal Palace and will make us a better side."
Dikgacoi joined Fulham in August 2009, but made just seven league starts for the Premier League side before moving to Palace in February.