Depends where you are geographically, as rates differ. Plus it depends on what amount of coverage you want (or need) to carry. For example, for PCI ASV's there are specific requirements for insurance.

Last I checked in my area (Detroit, MI), these were the approximate rates I was given:

1M/1M = $1,100
2M/2M = $1,600
3M/3M = $2,100

In addition to E&O insurance, those prices also included business income, liability, and property insurance ($50K, 1M/2M, and $25K respectively).