I wouldn't
The gum was barely edible when it was "fresh" in 1952, I bet (just like it was when I was growing up in the 80s.) lol. ... That's a great find. I have to do more nosing around like that on ebay. The only thing is it's sort of like a cruel tease because I don't have the money for it. ... You know what I wonder. I wonder if it's been opened, filled with junk cards with the knowledge that most likely whoever gets a hold of it will never open it. Isn't that a terrible thought? Huh. And, I'm usually too trusting!
I know someone who LOVES old gum, but I bet even she'd pass on the '52 lol
I did give her some 20/25 year old gum I found in some Baseball products and she took it...but I didn't see her chew it.
As far as the junk cards thing: Yeah, that's a concern, but not a huge one given that it's "graded"...meaning signs of tampering would likely have been spotted...mayyybe. But, I'm guessing people have done just that, and made tons of money too. The higher the value on something, the more likely a con is going to get involved.
But, it has that "What if?" appeal. With six cards in an untampered pack, you're likely to find a few cards in the $60 to $80 range, a couple cards in the $100 to $250 range, and maybe a $500 card...if you're lucky.
If you're REALLY lucky you'll find a card worth $5,000, $15,000, or $50,000...but there are very few of those in the set:
http://portasite.com/?category_name=1952-topps
Overall, if I had the cash, my bid would be much less than the $20,000 they're asking. I'd probably have one of the lower bids at a grand or two. Then again, if I was rich, I'd offer like ten grand and see if that'd buy it. And yeah, I'd bust that sucker if I managed to get it lol