Prentiss Hall , CCH and a few other publishing houses issue both legal and accounting editions of their publication in loose leaf binders and sell a weekly updated service at an additional charge. You might consider the same type of book with semi annual or even quarterly updates to subscribers.

If the prices were reasonable, you might be able to sign up a number of subscribers and have an on-going income. I might also suggest that if you wish to sell these books to the chipping community, you use part of the profits to hire a public relations person to promote it. People will not buy a product (no matter how good it may be) from someone they consider arrogant, non-apologetic and immature. This statement is not to be directed to anyone in particular, but if the description fits, learn from it and don't be so defensive.