Unfortunately this is very standard practice for any place that sells glasses or contacts. It is the same idea as the dispensing fee that the pharmacy will charge you when filling perscriptions. If you have health benefits some will only cover a portion of what they deem as an 'appropriate' fee.
For me to buy contacts for 6 months from an Optomotrist the dispensing fee is higher then the contats themselves
From Ontario Ministry of Health Re: Dispensing Fees on Perscriptions (just for an idea)
As part of their professional practice, pharmacists receive a dispensing fee for filling prescriptions. The dispensing fee compensates the pharmacist for providing professional services such as patient counselling, monitoring drug therapy, providing drug information to physicians and dispensing drug products. It also covers stocking of medication, maintaining patient medication records, general operating costs such as employees' salaries, rent, etc