AAAARRRGGGHHHH!!!! Buyer being unreasonable!

[BreadAndJamForFrances]

I am selling some books, London Transport type old books that were part of my dad's collection. My listings ended last Saturday,on Sunday morning I sent polite messages with an invoice to all people who hadn't yet paid. One person had bid on two items, a book and a large bundle of collectible photographs, so the invoice with a combined postage charge, and a message explaining this. I received no payment/message for two days, so sent another invoice.
Then I received a message that was worded politey but in a bullying manner telling me, not asking me, that I should only charge the postage of one item not two as they were going to the same address! I replied stating that I had already given a discounted postage charge and had to take into account the weight of the items plus wrapping (both collectible items so I wrap in card then a layer of bubble wrap then a postage bag to avoid damage) which determined the price, not the address. Also, I said that if he was not happy with the postage price (they were low value items) then we could mutually agree to cancel the sale.
Later that day I get a message saying he is happy to pay the postage price as long as that is the actual price of sending the items. So, I send another invoice - no payment still.
Four days after the sale I am getting fed up with the run around - he has confirmed he wants the items, but still hasn't paid for some reason. And I have heard no more, he has ignored three invoices so I opened an upaid item case. The next day I receive payment through PayPal with a demanding message - he wants me to buy a special set of commemorative stamps to use to post the items as he also collects stamps.......WTF.........I've spoken to eBay chat, they've advised me to send the items how I want to (pre-paid labels) but I just know that he will have some complaint when they arrive....you know the kind of thing, the page in this book published in 1972 has previously been turned, the camera angle in this photo taken in 1989 is not to his liking.........
Is there any way I can just cancel the sale and return his payment without him having to agree to mutually cancelling the sale???

For information, the items sold for £2.84, I am charging £4 for postage, for a heavy hardback book and 38 photos, including all wrapping.

You can refund and send cancellation request which he could refuse and he would neg, or you could send them and he would neg.

I would have opened an unpaid case days before tbh.

Yeah, I regret not opening unpaid case straight away, but as he has over 1000 positive feedback, I thought it would turn out ok.
I cannot see anyway to cancel the se without his agreement, or do I do it through PayPal?
Thank you

you can't - unless you send a cancellation request and he ignores it, then you will get your fees back.

Sorry for the questions, but I can't find much help on eBay.......so, should I send a cancellation request which he will probably ignore (he hasn't responded to my message yesterday telling him I am not prepared to buy special stamps) or should I just not post and wait for him to make his next move?
I have other related items for sale at the moment, so don't want him to be able to bid and do this again next week!

refund first via paypal then send cancellation request. Add him to your blocked bidder list. If he refuses the cancellation contact ebay saying he demanded extra terms which you couldn't meet. If he ignores it for a week it closes and you get your fees back.

Thankyou so much for your help

Ebay used to be so much easier, I haven't sold anything for 18 months and in my first two weeks back as a seller I've managed to attract some weirdos! And ebay definitely seems geared towards helping buyers rather than sellers.....and all these people seem to have a fantastic feedback score and comments!

because sellers are not allowed to neg, or leave negative comments for buyers anymore.

I would mark as item sent but not send them.

Wait for him yo ask and then say oh dear must be lost in the post.

Refund him.

Done.

I'd rather keep some things than send them to knobs.

and then have a case opened against you, a neg, final fees to pay and you have lied? Nope - not recommended.

FuckyNell - very tempting, but I have also got a good feedback record and don't want to jepardise it. I wish I hadn't bothered with the listing now, but I was trying to help my mum clear out the last of my dad's hoard...

I have sent him a short, concise message asking him to agree to a cancellation and I have blocked him. He is obviously getting a kick out this, I don't want to feed into it any longer.

I would do exactly as Lavender advises. Contact ebay if he negs you and ask for it to be removed. They can see from his messages he has made stupid demands of you. Total PITA.

Thanks nickstmoritz - having followed Lavender's excellent help and advise, I am waiting for his next move...I am sure he will neg me, but eBay had agreed with me that he was being overly demanding so hopefully they'll remove any negative comments.