Re: How Much?
What he said.
Basically, IPE and Reduced End are the only exceptions to the rule that advantages bought for HA's also apply to the STR that you can use to add additional damage to the HA (up to but not exceeding the base dice of HA). A HA with IPE will not be IPE if ANY STR used with it does not also have IPE as well. The Reduced End only applies to the HA. The STR used costs normal END unless Reduced End is bought seperately for it as well.