Personally, I wouldn't be allowing any more than the 4 days they get from ebay.

I guess if you mainy run auctions, then buyers probably won't be online when the auction finishes, so they will need time, but I can't see why that should take your normal buyer more than a day or so.

If a buyer doesn't pay, you just report it as an unpaid sale & get your fees back, as others have said.

Why do buyers get away with feedback? To give other buyers a sense of a particular seller's strengths and weaknesses.

Why can't sellers give feedback? In the old days, they could. But a few abused it. If a buyer gave a well deserved neg (and they could only leave short messages back then, but slow postage, not receiving item or receiving broken items etc don't take too many words), then some sellers would automatically give a neg back to a seller.

This was often in the days before paypal, where a buyer had no protection.

I did see one buyer ask a seller-Why have you given me a neg when i paid promptly? The seller replied-You gave me a neg so obviously it was a negative experience. That's not good enough-it was simply **bleep** for tat, a standover tactic, as in, don't dare give us a neg or we will neg you right back. 

It had to stop. It did. I'd say ebay had an avalnache of buyer complaints about it.

That doesn't mean there aren't some numpty buyers out there who don't give ridiculous feedback sometimes but most other buyers can spot a silly comment when they see one.

Don't resend an invoice, as for some strange reason Ebay uses the date you resend the invoice as the day of the sale therefore making you to have wait a longer period to wait to cancel the transaction due to non paying bidder.

You can also leave restrictions on certain accounts for example accounts with 0 feedback can't purchase or must be pre approved etc.

In addition to Sugar's advice, check the help pages about setting buyer requirements. It is possible to block any buyer with a habit of non-payment so they cannot buy from you!

eBay sends a payment reminder so you don't have to and sometimes if you do it will reset the sale date (thereby giving them another 4 days to pay) 

If they don't honour the sale cancel and block. Please use the reason suggested by sugar as that gives the buyer "a strike". 2 strikes and all sellers with buyer requirements will be protected from them.

We buyers need to be able to give negative feedback to warn others about substandard sellers. Some ace-holes abuse the system because they are entitled and have no sense of civic duty ( meaning all rights but no responsibilities - can't have the former without the latter!)

The non payment policy specifies 4 days.

I open a not paid case 4 days and 1 minute after purchase.  No reminders, no second chance.

Don't play games with them,  dump them

That is 100% up to you how long you give them to pay

If the don't honour the sale and you don't cancel the sale giving the reason buyer did'nt pay you will be charged fees on the sale and nothing happens to the 'buyer'

If yo do do that the 'buyer' gets a strike

eBay has'nt allowed buyers to be given negs since 2008, due to fluffy excuses from eBay