If the person selling the domain actually owns it and passes/transfers ownership to you...then you will own it.
I don`t think anyone on SUN can tell you if the person selling the domain on the two sites is the owner (without more information). If the ownership or name of the admin contact for the domain is shown and is the same in both auction sites, then it would appear the owner is using two sites to sell the domain.
You can look up who owns the domain.. or at least the domain record. Enter the domain name nad it will stell you if it is available and a link to the registration information.
If course the question is would the seller sell the domain for the lower auction price or higher auction price?
You can contact the Domain name by contacting the Domain name owner and know the final offer ,then buy Domain name that is for sale.You can contact the Domain name owner by using the Whois search at here Zippozap.com also get the free appraisal at here and then buy it,so you can know the worth of the Domain name and buy it.
Domain name speculators are also keeping an eye on Banks.com, being auctioned off by the UK company Names123.com. They expected a £1 million price tag for this little lovely. Bids were standing at around £100,000 and the auction closed on March 1st 2000. It's feared this name could be overpriced, after all the much better name Bank.com has already gone and that site is being developed as a community banking resource