http://www.auctionsniper.com/faqsnipes.aspx#snipes1quote:I tried to cancel the snipe but it failed
You cannot add, modify, or cancel a snipe if there is less than 5 minutes left until the auction ends.
http://www.auctionsniper.com/faqbasics.aspx#basics15quote:Both my manual bid and snipe were set to $725.
The help text IS misleading about when a charge is applied if the user has a duplicate pre-existing manual high bid:
If you placed a bid on eBay for $10.00, then you sniped with us for $10.00, the user would get a "HIGH BIDDER" status message. But if you place a bid on eBay for $10.00, then snipe for $15.00, then you will be charged a snipe credit and the status will be "YOU WON!"