Sneijder, 30, has been linked with a move away from cash-strapped Galatasaray and Southampton have emerged as a possible destination in recent days.
One stumbling block for the Premier League side, however, is the Netherlands international's wages.
Sneijder earns around £90,000-a-week in Istanbul.
"I'm interested but we can't pay him. I know that because his agent is my agent," Koeman said.
"[He's a] great player, a lot of experience, still fit physically and a lot of qualities because he played at the highest level.
"He played for Real Madrid, he played for Inter Milan and I think it's a great teacher for young players because he's talking about his experience and that's not only talking but he can show it as well and that's the best."
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