Hi Dawn.

You have two costs per unit volume:
(A) $13.50 / (5.5 cc)
(B) $17.00 / (2 oz)

You need to find the conversion factor to go from cc's to ounces, so we can compare these fractions using a common unit denominator.

When I type "1 cc in ounces" into Google, it replies "1 cc = 0.0338140227 US fluid ounces". So the conversion factor is that decimal number.

So (A) becomes:

$13.50 / ( 5.5 cc x 0.033814 oz/cc)
= $13.50 / ( 5.5 x 0.033814 oz)
= $13.50 / (0.195977 oz)
= $72.59 per ounce.

(B) becomes
$17.00 / (2 oz)
= $8.50 per ounce.

The bottle is WAY cheaper than the syringe, assuming you don't need the syringe itself!

Hope this helps,
Stephen La Rocque.

PS: Google is getting smarter all the time. You could even type in
"convert (13.50 dollars per (5.5 cc)) to dollars per ounce" and it will tell you !