"The wood is very expensive."
Translation:Το ξύλο είναι αρκετά ακριβό.
Το ξύλο είναι αρκετά ακριβό is a very awkward sentence for the The wood is very expensive. It translates better as The wood is expensive enough"
"enough" is a constant thorn in our side. If you say "enough" you have to compare it with something: "We had enough time to catch the train." means the "time" enabled us to catch the train. "We had a lot of time." is general. I usually give the meaning of "as much as is required". Here is one of my favorites: "We had a lot of chairs for the party but they were not enough, so many guests had to stand." Here's another from a composition: "When my grandmother had had enough children..." This means "as many children as required." :) So, on a course without much, or any context we need to keep it as simple and broad as possible. Thanks as always for your observations.
"quite expensive" is already an accepted translation. When it's a matter of adjectives in a sentence without much context we try to include as many as possible...many have been suggested by the community. It is I think "safer" to have the main translation the most neutral one as here we see "very" but we also accept others.