Small Craft advisor magazine Nov - Dec 2021 issue have published the results of their amateur boat building survey. Some that might be of interest is the cost of building which are as follows:
Cost per m - $1 476.30
Cost per kg - $35.20
Hours per kg - 3.3 hrs
Hours per m - 157.5 hrs
Bare in mind that these figures are the average for many different small boats ranging from Kayaks to small power and or sailing keel boats but still might help in comparing different designs. I think that most of the amateur builds of followers of the above magazine are timber/ply of some sort or other and are generally less than 28 feet.
The above are based on pre 2020 costs so might see significant material cost increases.
