Very curious about expenses
Ken, while that question is more specific, the answer remains somewhat ''it depends''. You do sound like someone with economical tastes and lifestyle, and the fact your boat is small certainly helps...but over any meaningful period of time (let''s assume 1 year), significant variables can still make quite a difference.
Will you be sailing regularly and/or over longer distances? If so, the boat''s gear will wear faster and so maintenance costs increase. Will your engine be your only source of DC power aboard while primarily anchoring out? If so, that will add a bit of diesel fuel and maintenance costs (filters, lube oil) to the budget (vs. e.g. having sufficient solar panels to meet your needs). What condition is the engine in? You may not really know, as often it isn''t until one starts relying on systems regularly that problems make themselves known.
Bottom line: You may find you spend <$100/month initially, if you stay in one place and your boat starts out in good shape...or it could be more than that. As a general thumb rule, longer term (over a period of a few years plus), full-time cruisers report a boat''s annual budget typically is ~5% of the value of the boat. Boats that are used offshore sometimes will require ~10%.