My ticket for Carmen on October 30 was exactly $250 including tax & s/h. It's an old production (the Zefirelli) but because the opera was Carmen &, perhaps, because the conductor was Domingo, the prices were such. It wasn't even a center-orch seat but in the right-orch block. Excellent show. My husband & I aren't complaining...but it was incredibly pricey for an older production.
I just looked up the Oct 30 performance in the Met brochure & the top ticket price was $215. As tax is included, this must mean you paid $35 per ticket shipping & handling. That is, indeed, outrageous. Were they ordered from the Met? Could they have been left at the box office for that evening's pick-up for less, do you know?
As far as "prime", the side sections, first 6 or 8 seats off the aisle are considered still prime. Personally, I prefer them to the center of a row in the middle section as there are generally fewer heads in front.
As far as charging more for an individual artist, no company can do this as it would mean a statistical nightmare should that artist cancel.
If they don't charge more for a great conductor like Levine, de Billy, Thielemann, they certainly can't charge more for Placido. Great singer & musician though he is, he has yet to become a great conductor.