I assume there are other costs associated with operating an online venture that brick and mortars do not have to shoulder
That would be a different discussion unless those costs are tax-related.
IMHO, if online retailers and B&M are in competition, they should be able to compete based on the actual costs and advantages of their respective modes of doing business.
It's not fair that one side has to deal with the burden of consumer resistance created by the fact that the other guy doesn't have to charge taxes. The cost differential that creates for the end consumer is totally artificial.