Explain Jake’s statement, “Enjoying living was learning to get your money’s worth and knowing when you had it.”

If I recall correctly, Jake makes this statement about the
Greek Count that he and Brett meet and pal around with for awhile. While the Count is
infatuated with Brett, instead of being jealous and controlling like all of Brett's
other men, the Count appreciates Brett for the free spirit that she is, and he enjoys
being with her. He enjoys buying Jake and Brett expensive dinners and champagne and he
does not feel like he is being taken advantage of because he wants
to do it. He is wealthy and knows what quality is. He recognizes and enjoys
good cigars, good wine and good food. In this, the Count is a foil to the other
characters in the novel because his money is actually bringing him pleasure, unlike the
other lost characters in this depressing novel.

So, what
Jake means is that the Count knows what quality is, does not mind paying for it and
enjoys it when he gets it. This is living. The count is one of the few characters in
this novel that enjoys life.