Talbot, your point about cost is appreciated. My costs for refairing and repainting the hull on my DS1 are perhaps as much or more than I paid for the boat, but they include money for renting a larger garage to do the work in. Locally, the DS was apparently never sold in the same numbers as in other parts of the country so I haven't seen too many advertised in easy driving distance, so sourcing a hull in better shape was not necessarily an easy option (and to that add the benefit of "knowing" that particular hull - no hidden problems).
If I calculated time spent, I could buy new and still break even - but then, a bit of restoration work is in itself a hobby. Yes it's work, but entertaining work. Especially when there's a bit of challenge figuring out how to best attack it.
Any task that I can accomplish where the cost of materials are below market value for the ready-made equivalent are particularly satisfying.
The UK-based sailing magazine Practical Boat Owner (very entertaining publication by the way, precisely because of where it is written) had a feature over the last year where they restored a 25' (or so) "project boat". They had the entire editorial team pitch in and heavily worked their contacts to get deals. When they totaled up the costs, it was, of course not competitive, but they came to the conclusion that despite that, it was an an enjoyable and defensible project.
New or old (or restored with a bit too much work/materials) you still need to replace sails, rigging, etc. on a somewhat regular basis. Distributing all this over the years means that after a decade or so, the cost/year is not all that strongly affected. At least it seemed to me - I finally gave up tracking boat expenses, because they seemed to depend on how many times I hit the marine store, not what ended up getting done on the boat that year.
-- Before you ask, I'm between 1 to 1.5 K per year on this boat, depends whether I calculate in current dollars or not.