Oksana to Mel: Our Baby Needs More $$$$$

9/3/2010 12:00 PM PDT

Oksana to Mel: Our Baby Needs More Money - Mel Gibson Oksana Custody

Oksana Grigorieva is asking the judge to make  Mel Gibson buck up -- WAAY up -- by increasing her monthly child support from $5,000 a month to more than $40,000 ... sources tell TMZ. 

As we've reported, Mel currently pays Oksana the tidy sum of $5,000 a month in child support for baby Lucia, and also pays for the Sherman Oaks house where they live.  But we're told Oksana  now wants nearly 10 times what she currently gets.

Here's what's interesting.  Our sources say Oksana gets $2,500 a month in child support from Timothy Dalton -- the father of her 13-year-old son Alexander. 

It's a tough sell convincing Judge Scott Gordon that a 9-month-old baby needs nearly 20 times more money than a 13-year-old boy.

One source scoffed, "Lifestyle is not an issue for a 9-month-old. Think she knows the difference between a Ford and a Bentley?"

We're told Judge Gordon has not ruled on Oksana's petition for more dough.  Holding breath -- not advisable.