Question about 1990-91 Upper Deck Hockey error

[BigStarrCards]

Just wondering how rare the Wayne Gretzky and Theo Flurry error cards are.I was at a card show today and
some one had the Gretzky with the Flurry Back and the Flurry with the Gretzky back. I had not seen these
before and perhaps they are very plentiful.But if anyone here could PLMK I would appreciate.it.

[cjb]

I collected a lot back then and this is the first ever time i've ever heard of this type of error. So it must be very rare

Don't know how much it's worth.

Keep in mind that just because it's probably a rare error card doesn't necessarily mean it's worth a ton of money

[BigStarrCards]

I collected a lot back then and this is the first ever time i've ever heard of this type of error. So it must be very rare

Don't know how much it's worth.

Keep in mind that just because it's probably a rare error card doesn't necessarily mean it's worth a ton of money

I am not concerned about the value. Weather its $1 each or $500 each. It does not matter to me. I am just looking for a bit
of information on how rare these may be. We do have two pretty good players involved here. And it certainly was a corrected
error.Back in 1990 I was only collecting baseball and a bit of basketball so I have zero knowledge about this. But over the
last 35 years a person would certainly heard about it.And I notice that even Beckett does not indicate an error like this is out
there. So I would agree that it is likely pretty rare. Likely something that got caught in a flash and only a few sheets got released.
But who knows.Thank you very much for answering my thread.