I purchased new lenses; I had some existing frames which I reused. Granted the non-progressive single vision lens had a complex prescription, with prism adjustments and such. But there are no special coatings except anti-internal-reflection. It was NZD $500, remounted in old frames I supplied.
I looked down at a prescription laying on the desk and saw someone had spent very close to NZD $1,000 for a single pair glasses.
I wasn't thinking straight. I should have just gotten the prescription, then mail-order glasses from the US.
The price would have been sub $200 even with frames and delivered.
As you'd expect I don't buy eyeglasses everyday, but I was happy with three orders from glassesusa.com. Granted I had to guess my head width. Delivery time would have probably been one month versus two weeks.
You can screw over your local eyeglasses company by trying on frames locally, looking on the inside frame for a series of numbers. The first number between 45 and 60 should be your lens size.

Obviously you're going to missing out on the perfect-for-your-face frames, and post-adjustments.
Not helping is that most frames worldwide are manufactured by a single company, named Luxottica. They control 80% of the major brands in the NZD $45 billion global eyeglasses industry.
It would have probably been a good idea to fly to another country, get eyeglasses plus a spare, and prescription sunglasses, and return home than buy them here. At least I would have gotten some vacation time out of it.
Between dental bills and eyeglasses, I'm getting killed for medical costs recently.