388 total cost of ownership

Annual Yanmar service would be $400-800, less DIY. Remember also, to  change the Sail Drive oil, the boat needs to be hauled out. A haul out here costs $300, sling days extra.

When do you propose to change the sail drive seal?- Every 7 years, or not bother. some leave longer in spite of Yanmar recomendations?

New rigging- Every 10 years, or not bother. What does insurance co say?

Running rigging, Halyards can wear.  Sheets to main & jib every 5 years or wear gloves?

New sails -Every 6 years, or longer if you do not care about performance

Extra sails- Code zero is a nice to have.

Anodes- Quite expensive. Can you change using a diver?

Cost of visits to other marinas- Presumably you intend to go places

Antifoul & prop clean needs doing every year, unless you want sail like an old dog

Surely you need to factor in these costs & divide by an annual sum

I'd suggest that an effective use you could put a spreadsheet to would be to get the service schedules for every bit of mechanical and electrical kit, list and and cost each item on those schedules for parts, labor if you need a pro, and periodicity.  I'd also research if there are any items that seem to fail early. That way you'll gain a sound appreciation of the mechanicals of your boat and deepen your understanding of it.  That should give you greater confidence in it and mitigate against breakdowns.  

Do similar for sails, running/standing rigging replacement, electricals and shipwright items like winches, anchor chain etc; consider when you're likely to want to upgrade/replace items and how much to want to set aside for whatever shiny, expensive item you'll inevitably want after seeing it at a boat show.  

You should find that some years will be way more expensive than others even before you factor in mooring fees, the plethora of running costs and repairs which are a real wild-card.  Trying to forecast the running costs of a boat that's used a lot with any high degree of accuracy is a bit like forecasting Bitcoin. As I wrote in an older post, my missus doesn't mind how much I spend on the boat as it means I don't have the money to spend on another woman - and she's so right.  She calls the boat 'The Mistress'.....