How long should I wait to send another bidder a second chance offer

[vortex_747]

I've listed the same item multiple timers now on eBay and it always sell but the winning bidder consistently chooses not to pay. Earlier today it sold once again though the winning bidder asked me questions about the item right after the auction had ended (the answer was in the listing description) but I replied anyway and haven't heard anything back since (going on 12 hours now). I doubt he will pay, so how long should I wait before sending a second chance offer to another buyer? Looking at his feedback and the comments other sellers have left it seems like this buyer doesn't pay for a large number of his purchases. 

[8990045]

One other trick you  can use is the blocking of those bidder that win an item and don't pay,when these members are set on your block list they are not able to bid on any of your item anymore.