I couldn't tell you why you received $7800.00 instead of $7500.00, but I do think you should check with your accountant. I've posted some information below in reference to the Tax Credit for First Time Homebuyers for 2008 and 2009. I hope this helps. It's my understanding that the new bill that just passed is for purchases made in 2009 and will not have to be paid back over the course of 15 years.
FIRST-TIME HOME BUYER CREDIT First-time home buyers are eligible for a refundable tax credit equal to 10 percent of the purchase price of their home, up to $8,000, if they made the purchase after Jan. 1, 2009, but before Dec. 1, 2009.
Unlike a similar credit that Congress provided last year, you donâ€™t have to pay this one back over 15 years. The new credit, however, does phase out for individuals with incomes over $75,000 or married couples with incomes over $150,000 who file their taxes jointly. Also, you forfeit the credit if you sell the house within three years.... more