Incidentally, if it's the blue one, the listing will be cancelled if you say you might end the listing early. The bastards that run Ebay are nearly as bad as the scammers.
They will only do that if somebody complains. And even then it's a slow process because there is no specific complaint category for that, so it needs a human to read the complaint. A lot of the categorized ones have require no human intervention, the complaint kicks off an automated process that looks for combinatinations of words and phrases that would indicate the auction does actually fit into those criteria.
Anyway you may not realise it but "advertised elsewhere reserve the right to close the auction early" is widely used as code for "make me an offer outside ebay". The etiquette for these ads is to ask the seller how much the item is advertised elswhere. They respond with the asking price. You say done, and you've "bought it now" with ebay getting nothing but the few pence it cost to list the item. Not that my old Peugeot was obtained in that way, you understand.