Tiny Bubbles

Any time I try these super-macro shots I say "so what do you think this is?". But people always guess the answer correctly, so I've given up.

This is a close-up of a bottle of "King Of Shaves Alphagel Shave Gel". It has lots of little bubbles in it... and that's what the picture is of.

So, if it has lots of air inside it, and the product is priced in terms of its volume (this is a 175ml bottle), how much are we paying for the air that is trapped inside the gel?