So, to recap: 2 pairs of glasses, prescription lenses in both, clip on sunglasses:
Total (with $4.95 shipping): $58.80
I'm not lieing.
Each pair came in an opaque white case, with a cleaning rag in both... for under $60.
I know you can get single prescription and bifocals. I'm not sure about trifocals. All you need is your prescription, and to measure the distance between your pupils (easily done in a mirror with a dry erase marker and another pair of glasses).
Check it out if you're part of the glasses wearing club, it's well worth it, and depending on your insurance, it could be cheaper than your eye doctor, where my last pair was over $300.