Mark Robinson believes Dustin Martin would be "extremely greedy" to leave Richmond for North Melbourne at the end of the season.

The Herald Sun chief football writer understands there is approximately a $2 million difference between deals on the table from both the Tigers and Roos, but says Martin should decide to remain at Richmond.

With North's offer of $1.5 million a season shading Richmond's offer of $1.2 per year, Robinson believes both are great deals, and says suggests Martin should not turn his back on his current club.

“I think Dustin Martin would be terribly greedy to leave,” Robinson told SEN’s Crunch Time on Saturday.

“I think he has been offered a really good deal to stay at Richmond… Richmond have been a really strong component of his life.”

“Is it right that a father from afar says - if he does - just take the money, it’s really important?

“Life’s not all about money. He’s got a big start. He’s going to get between $1.1 and 1.2 million (a year at Richmond).”

As well as slamming Martin's decision should he leave Tigerland, Robinson also took aim at free agency, saying the current system in place is being exploited.

“I don’t like what it does to the fabric of footy,” Robinson added.

“I find it staggering that a couple of years after it started, one of the best players in the competition is going to leave his club purely for money, if he leaves.

“This is not what free agency is about, is it? Ripping a young player out of a club?”