Posted By:
CatIt's 10%. The problem is you are dividing by the wrong denominator. You can't pick and choose numerators and denominators:
Current bid is $1,000. Which means you will pay $1,200.
The bid is raised to $1,100. You pay $1,320.
$1,320 is 10% higher than $1,200.
You need to include the vig in both equations.