Off hand, I wouldn't know of standard period... personally, I think a week is too long. If you are opening up discussions on a purchase by offering a bid, I would expect a response within 24 to 48hours, if the auctioneer is busy with many properties on the go, then s/he may take longer to contact the seller & then the availability of the seller & their decision... If / when you are talking to them, ask them when you will be contacted again regarding your bid.
Just to let you know that this is the "fun" period... you might be lucky, a few bids & it's yours.. or other "bidders" may be appearing... so make sure you have your "top price" in mind & try not to go above that... cash is king at the moment, so if you are ready to go, then make sure you state that to the auctioneer... if you have a property to sell first, then there might be less enthusiasm from the auctioneer.