Not sure if I agree with Coravin's claim that each capsule allows you to access 15 glasses of wine.
I trust that they've done the study to prove this, but the devil's in the details. It is quite possible that each capsule allows you to access 15 5-oz pours from 15 totally new bottles which would limit the amount of Argon necessary to refill the partially emptied bottle. But, in real life, when you access the same bottle multiple times, you will be using much more argon gas to fill in the removed wine.
Long story short . . . one capsule lasted me:
--2 test bottles (removed ~12 oz from each; will open again in 1 month to test against "fresh" sibling bottles)
--1 bottle accessed one-time last week (~10-12 ounces removed from first opening)
--A few bottles for puncture test only (minimal gas released, I believe)
--1 bottle opened a few nights ago . . .5-7 ounces removed. Same bottle opened last night and was out of gas.
If it's purely a volume removed/replaced equation, Coravin suggests the Argon gas cartridge is good for replacing 75 ounces of liquid. My first capsule lasted ~50 ounces of liquid removed. I did not do precise volume measurements so my 50 oz estimate may be a little off, but I am sure I am nowhere near the 75 oz. estimate Coravin provided.
Going to do another "longevity "experiment" to really test the longevity of a capsule once I get more capsules!