Which of these is more or less expensive, by how much?

I have the option to either:
a. Pay a fixed $35 total co-pay if I get an eye exam ($10 copay) and either new lenses ($25 copay) for my current frame or a new lenses with a cheap frame (one that retails for less than $120). VSP (insurance/savings program) pays the rest. (If the frame costs over $120, then I pay the co-pays and the amount by which the frame exceeds $120; VSP pays for the rest.)
b. Get a 15% discount on a contact lens exam and have VSP pay $120 towards the lenses and exam. I pay the rest

If the contact lenses plus the discounted contact lens exam cost more than $155, then the eyeglasses (with either my current frame or an inexpensive new frame) would be less expensive.

My many
Disregard the two words "my many" at the end. Cut-and-paste error.
I am NOT saying that I am getting both and asking whether it would be cheaper to pay for and use VSP for b or vice versa. I am saying that I am getting one or the other, not both, and want to know how much contacts would cost with VSP without glasses versus the fixed $35 I spend if I get glasses without contacts.

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Orignal From: Which of these is more or less expensive, by how much?