hi bro,
marine cabinet are more ex because their are built with proper support. the supporting beam are the pillar of the structure.
why not u dont mention "marine" when customise the cabinet? it will definately be cheaper but u will have nightmare and worry if the cabinet can have the support needed.
as for teak, its not advisable......they can infested very easily....thats what happen to my teak tv consol and dining table....got small ants......hopefully not termite..
ultimately, the choice is urs.....pay cheaper, get a normal cabinet and worry, or pay abit more and have no worries.