Aloha ahiahi!
A common phenomena among coin collectors are that they often over value their collection, and therefore ask for coins that actually has a greater value than their own.
Me personally, am sometimes asking for silver, but knowing the coins' worth, I can give 10 or even 15 coins for one silver. Never 1—1. All you can do is kindly deny the swap.
If your looking for world coins, I have lots availavle for swap. I'm downsizing my collection, so if you willing to trade silver for an avwrage of aboitt 10 coins of mine, please feel free to send me a proposal. However, I wish you a great day, and happy collecting!
Aloha!