Well, I expected something like this from this subject, so let us know the colleagues the full story. You are tended to publish manipulative information. Why didn't you publish your last message, after which you blocked me? Others would like to see it, don't you think?
You wrote me in 15.02. and initiated the swap. Here we can see the screenshot from your side (please note XF at 300 guarani, that will be important).

And from my side. Only one coin is visible because dennis_hanoi selected 31 coin and it is not possible to put it in one screenshot.
Than let us see all the discussion from beginning till the end.
For it would be more interesting, let us take a closer look on your XF 300 guarani.

Every reader can decide himself what kind of "XF" is it. I would be very disappointed to receive it.
Regarding his links to Ebay all the sane people knows how Ebay works. If he likes the links, here they goes:
Japan. Sold for 11,50 euro.
https://www.ebay.com/itm/Japan-1000-Yen-1964-Olympiade-Silber-vz/293343438055?hash=item444ca1a4e7:g:UHcAAOSw2VZd1~nc
It does not take much to find something sold cheaply or listed expensive, and than trying to manipulate with it, right? Why do you think that other people does not understand it?
Piastre. Sold for 22 euro
https://www.ebay.com/itm/1-single-trade-Indochina-French-1900-silver-/352911296207?hash=item522b2706cf%3Ag%3AousAAOSwkMNeB6PV&nma=true&si=3cT9mcLF7t7PMk7Wrlgv%252FweFb0o%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557
That's in case if his piastre is the same XF as Paraguay. That one I did not see, so cannot confirm.
And just to laugh, example of manipulation in dennis_hanoi style. My 25 gulden is worth 138$
https://www.ebay.com/itm/1973-NETHERLANDS-ANTILLES-Huge-4-5cm-SILVER-25-Gulden-Coin-JULIANA-25-Yr-i73765/233077495773?hash=item36448057dd:g:O5cAAOSwcaBcK~i7
Of course it is not, but that is the way how he is trying to act. Many people tries it and I am fine with that. Just this one crossed the red line.
So I think that dennis_hanoi tried to cheat me with condition of Paraguay coin, that intention failed, and than he become mad about my proposal, instead of just accepting or denying it. Probably he should use some kind of sedative pills, that could help him to act in more reasonable manner.