How many bottles, if any, have you used up? Do you get "back-ups"?

#1
I've been thinking - I can't seem to be making much of a dent in any of my bottles, partly because I apply very little oil having to be concisous about other people at work and partly because I rarely wear the same oil even twice in a row and usually go through several a week to keep things interesting. Has anyone here actually used up a full 1/4 tola bottle and if yes - how long did it take?

Another question that's somewhat connected to this - do you get backup bottles of the oils you really love?