The actress - who has an estimated wealth of around $120 million - has splurged on several lavish presents for her actor boyfriend since they started dating 11 months ago, including $12,000 on a leather jacket once owned by James Dean, a $450,000 Genn Ligon painting and two motorbikes, a $33,000 Ducati and a $24,000 Harley Davidson.
Additionally, Jennifer is also said to have spent $1 million on furniture and artwork for their new Los Angeles home and $750,000 for a feng shui expert to assist with their $10 million make over on the property, as well as funding the couple's numerous holidays.
A source said: ''Neither Jen nor Justin seem embarrassed that she is the main breadwinner.
''She is in a comfortable position so why not spend money on the man she loves.''
However, the spending isn't a one-sided affair, with insiders claiming Justin bombards Jennifer with gifts.
The source added to Britain's Grazia magazine: ''Justin loves buying Jen little gifts and going out of his way to show how much he cares. This is not a one-sided relationship at all, and Jen feels she is the luckiest girl in the world.''