Dprice is generally correct. In very strict terms, however, the "tax" is what is referred to by most to be the things needed to get the bike to run and sound proper...in other words to undo the EPA mandated jetting (carb bikes) and noise restrictions that are on the bike from the factory. (EFI bikes require computer re-mapping instead of jetting.) Since the restrictions are mandated by the feds, and you have to pay extra to get your bike "right", hence the term "Harley tax". Something you would not have to pay if the feds were not involved. For a Sportster, it consists of complete exaust or slip-ons, SE air cleaner and rejetting. Minimum cost for that stuff (do it yourself) is around $220.00 Pay the dealer to do it, add more labor) or do it yourself. If you want to change out the entire exaust, add about $400.00 A gazillion different options...go to
www.sportster.org for the skinny on all the different changes that are possible. Too many to list here...
'03 XL1200S on the way...