Calculating your Taxes according to the Tax Bracket, with the information you provided, the difference is actually $2500.00. This is assuming that your Taxable Income changed from $50k to $60k and that you are Single. Your Taxable Income is calculated by:
AGI - Deduction(standard or itemized) - Exemption(s)=Taxable Income
https://www.irs.gov/pub/irs-pdf/i1040tt.pdf
When you look at the Tax Table you must use your Taxable Income to figure the Tax. A difference in Tax Due from a $10k increase in income is not out of the question.
I have attached screenshots of the IRS Tax Table Sections for $50k and $60k of Taxable Income. The Values used are for Single Filers; $60k of income = $10778 in taxes; $50k of income = $8278 in taxes
