A while back, I did a post where the issue of sales tax was brought up. There seems to be some controversy over this point, so I figured we might clear it up.
In summary, an IBO is charged sales tax on the retail price on products for the region you are in. If you sell an item to another tax jurisdiction, you are required to collect all the differing sales tax and send it to Quixtar with a Tax Adjustment form.
If you use an item yourself, you have the must fill out the form and get your difference back.