Ideal Med boat size? (Any hard size related costs)?

[Tranona]

Cheap stuff/teak decks? Is there a cheaper type of teak available other than the obvious vaneered stuff?

depends on how you define "cheap". Many of the higher class yards use thick old growth Burma tea which slowly wears down over the years. Others use thinner poorer quality teak although one of the main determinants of life (and costs of renewal) is how the teak is attached to the deck and the nature of the deck to which it is attached. It is perhaps inevitable that lower cost boats generally will have less money spent on materials, although obviously there are exceptions.