Going back to the OP question on how long it will take. If the interest is 7.5% on 150,000 and you pay 2,000 a month it takes:

Loan Calculator

Loan Balance: $150,000.00

Adjusted Loan Balance: $150,000.00

Loan Interest Rate: 7.50%

Loan Fees: 0.00%

Loan Term: 8.5 years

Minimum Payment: $2,000.00

Monthly Loan Payment: $2,000.00

Number of Payments: 102

Cumulative Payments: $203,040.64

Total Interest Paid: $53,040.64

Note: The monthly loan payment was calculated at $1,780.53 for 120 payments (10 years). Since this amount is less than the $2000 minimum, the term of the loan has beenshortened to 101 payments of $2000 plus a final payment of $1,040.64 .

It is estimated that you will need an annual salary of at least $240,000.00 to be able to afford to repay this loan. This estimate assumes that 10% of your gross monthly income will be devoted to repaying your student loans. This corresponds to a debt-to-income ratio of 0.6. If you use 15% of your gross monthly income to repay the loan, you will need an annual salary of only $160,000.00, but you may experience some financial difficulty.This corresponds to a debt-to-income ratio of 0.9.

For 3,000 a month:

Loan Balance: $150,000.00

Adjusted Loan Balance: $150,000.00

Loan Interest Rate: 7.50%

Loan Fees: 0.00%

Loan Term: 5 years

Minimum Payment: $3,000.00

Monthly Loan Payment: $3,000.00

Number of Payments: 61

Cumulative Payments: $180,415.43

Total Interest Paid: $30,415.43

Note: The monthly loan payment was calculated at $1,780.53 for 120 payments (10 years). Since this amount is less than the $3000 minimum, the term of the loan has beenshortened to 60 payments of $3000 plus a final payment of $415.4

It is estimated that you will need an annual salary of at least $360,000.00 to be able to afford to repay this loan. This estimate assumes that 10% of your gross monthly income will be devoted to repaying your student loans. This corresponds to a debt-to-income ratio of 0.4. If you use 15% of your gross monthly income to repay the loan, you will need an annual salary of only $240,000.00, but you may experience some financial difficulty.This corresponds to a debt-to-income ratio of 0.6.

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ok so now we've established that it will take you this long to repay $150,000

$3,626.84 = 4 years at 7.5%

$3,000 a month = 5 years at 7.5%

$2,000 a month = 8.5 years at 7.5%

$1,780.53= 10 years at 7.5%

and

$1,726.20 = 10 years at 6.8%

From this the OP should be able to make some good determinations as to his question.

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For reference, the tool I used is:

http://www.finaid.org/calculators/loanpayments.phtml This tool is good to help estimate taxes: --LinkRemoved--