>>And it was promoted...and do I lose the 'promoted' fee?
No. If you cancel the eBay transaction as buyer requested the ad fee will be credited, along with your final value fees.
>>And should he formally send a cancel notice through the item?
Buyer can only request a cancellation through eBay's system for 1 hour post sale. After that hour their only option is to send an eBay message.
>>If I wait 4 days and cancel(refund) this guy can still leave feedback?
Yes, doesn't matter when you cancel, they can still leave feedback. The only cancellation reason that blocks feedback is cancelling for non-payment and that's not possible here since the buyer paid.
>>He got blocked of course immediately.
That means his messages are also blocked. You can send him messages, but he cannot send you messages. On his end it will appear his messages go through, but eBay will not pass those messages to you, and buyer will think they are being ignored.
>>This guy buys on a Sunday and I mark it 'mailed' on Monday morning and then later emails me he wants to cancel it.
It's not uncommon to get cancellation requests after an item ships. I usually tell my buyers it's too late to cancel because I already shipped, but they're welcome to refuse the package and I'll refund when tracking confirms a "return to sender" was processed and the package is on its way back to me.
You didn't use tracking, but you could follow a similar process if you want - cancel/refund once the item is returned.
Another option: buyer could file a formal return request upon receipt of the item with the reason 'changed my mind'.
Of course you can cancel and refund without requiring a return if you prefer; you said it's a small $ amount.
