Tac, sorry about the link... ... Their Tin is 99.9995% pure, so that is probably the reason for the price.

As for the dealer, did they look in the wooden drawers below the reloading stuff...

I will have a scout about and see what I can find. Does it have to be Tin?

Another thought is you could use 60/40 solder and calculate the correct amount to add. It is only lead, tin and a bit of resin which will burn off.

Mark