1959noni

"I have been watching an item it was showing 1 bid for $1000 for the past few days, now still showing "1 bid" but for $1200 and I  the duration of sale has been extended"

As requested in #1, could you please post the title of the auction here as unless it's done in the first 2 hours of submitting the listing , sellers haven't been able to extend the listing duration for over 5 years:

http://announcements.ebay.com/2007/06/update-removal-of-revise-item-duration/

***super_nova

They can put up the price  as long as there are no bids or they removed them.

Listings with bids can't be changed even if the Seller cancels the bids. The Seller would need to cancel the bids and end the auction before the last 12 hours then relist the item.