A nuclear bid as a snipe is very, very dangerous. Here's why...
Fred sees a Widget and thinks "I'll have that!" and places a nuclear bid of, say $5,000,000
Now, say this then puts his bid in as $510, no-one will know his max.
Along comes Mint, decides the Widget is a must-have and places a nuclear snipe of $10,000,000
When the snipe gets placed, ebay accepts the snipe at 10 million dollars and its proxy system then comes into play.
And voila, the item is yours at....
$5,000,010 (or maybe more, depending on what the next increment is).
You're the winner but I doubt if you'll cough up so everyone is annoyed and no-one wins.
Now that's the disadvantage of nuclear snipes!
If you have decided that Fred has placed his max at $510 then a nuclear bid is OK (still risky but OK) but if he's equally keen to win then watch out...
Hope that makes sense!
R2