In Walden by Thoreau what does "dear", in context mean?

In context, the use of the word "dear" is a way of saying that something is regarded with affection..... something precious. One example of this can be found in Thoreau's remark "living is so dear", meaning that life is something to be valued and cherished.

I did not wish to live what was not life, living is so dear; nor did I wish to practise resignation, unless it was quite necessary.