All of the above. If your attorney is knowledgeable and thorough, and
if what you have designed is not a unique, out of left field, or is kind
of a new twist on an old idea, plan on spending ten to twenty times as
much. Four year maintenance will run nearly as much. Ditto on telling
people and talking about it. Could easily wipe you out in court if you
would have to defend against a later similar product.
If there is a major library nearby you may be able to search patent
records to see if what you are thinking about already exists as a
patent. Also, it will give you an idea of what the legal eagles refer
to as "prior art": devices already under patent (whether currently
protected or expired) that do what yours does or the inventions that
have lead up to your design.
In any event, good luck and keep your mouth shut.