That's a ridiculously good price, yes grab it!
On the switch test of the office card, that's a good idea, and more pertinent is whether the office machine does the same thing with the questionable card.
I'm sorry that the back is no better at all after this time and yes, you should be getting more than what amount to blank stares. The Mayo referral sounds a little more proactive and I hope they get you some relief, fast.