I'm guessing your talking about a trailor sailor , if you are We had one and other than: comfortable PFD's, Basic Map
GPS,
VHF radio,
solar pannels for the flat
screen TV, new
sails and updating
rigging,
bottom paint, cost of truck to pull it, tune up on out board, at least 2 anchors,
mooring buoys, running all lines to the
cockpit , If the
boat your looking at already has these things there's no real cost.

Oh yes there is probably a
boating test/licence also tab's and tax licencing yearly.
Good luck!! Some times I wish I still had our 26ft trailor sailor.