Debbie Debtor obtained a $5000 loan from Shady Shark to purchase a used car, and granted Shady Shark a security interest in the car. Six months later, after she had paid off exactly $500 on the loan to Shady Shark, Debbie sold the car to Bob for $3,000, which she deposited into her bank account bringing her total bank account balance to $4,500. Debbie then decided to pay bills for $1,100, buy groceries for $300, and spent $600 shopping (all paid from the money in her bank account). The following week Debbie received her paycheck for $1500 and deposited it into her bank account brining her overall balance to $4000. Debbie had no other withdrawals or deposits to her bank account.
How much of the money in the bank account can Shady Shark successfully claim as proceeds of his security interest in the car?