You shouldn't have any issues buying one in Europe or Australia and bringing it back to the US other than possible customs fees and *maybe* S&B USA giving you some flak if you ever had to send it in for service... The European models have a different warranty because of some EU specific warranty laws, and not sure how they would handle that along with the issue of having a US patent infringing scope in their US service center.
Not sure if they can still ship S&B here because of dealer agreements, but possibly Optics Trade could get you one... Years ago they always had better prices than US dealers on S&B, but typically with a longer wait time.