i think there's no way out unless you wanna get your trader standing affected permamently or if you're lucky Sedo's infamous Security & Compliance Team will review it, if you didn't have any screw-ups before (like not paying a name you won or selling a name & not delivering it) Sedo might let you get away w/one but only one slip, any slip later you're out for good, no 2nd chances
SDSINC is correct, the guy offering you lots more can bid on the auction but unless the name is worth a lot and a few others get to bid up the price by a lot ( how many days are left in that auction ? ) it's not likely you'll end up w/a winning bid near $800, ie your new guy's bid will be $800 (his max bid i guess) but all his entry is gonna do is raise the price to $70 as reserve was already met at $60 so you'd need others bidding high amts as their max bids, ie above $800 so the current price can get to $800, otherwise ea new bidder, whether it's a $200 or $500 bid, will simply cause the price to go up to that new bidder's max bid so it depends on whether there's demand for this domain and how many ppl will enter setting high amts as their proxy bid. Still, due to the high max bid your guy will enter, any other bidders will immediately be brought up to their max bid, if i bid $200 as my max that's the new price, if my gf bids $500 as her max that's now the new price & so on, i assume it isn't a hot name cuz you allowed it to go to auction for $60 so as SDSINC & PinkMisfit said, that was your reserve, no-reserve/no min bid auctions are risky no matter how good the name, just ask a guy i know who got $105 for an NNNN.com just wks ago after a long auction on another site
PinkMisfit is correct, once someone offered you $60 for the thing & it got sent to auction you gotta eat the ending bid. No way they'll let you get out of it (Bassel is right too, he took the words rite out of my mouth, lol...cancelling a running auction is much less egregious than cancelling one w/a winner, that's how i as a seller see it but Sedo won't distinguish) i don't think they'll cancel the auction under any circumstances, at best they'll let it end & if you don't deliver the name at winning bid you'll be in hot water. DocCom is also rite, you gotta wait till auction ends and you can't even entertain another offer even w/in Sedo for $800 or even $8. If you do, I highly doubt Sedo will look at their 10% commission on, say $800, & conclude it's better for them too, it goes against their pockets but they're real formal there. Hope this helps, good luck